Permanent magnet synchronous motor inductance parameter identification method based on operation state correction

Abstract

The invention discloses a permanent magnet synchronous motor inductance parameter identification method based on operation state correction, and belongs to the technical field of permanent magnet synchronous motor parameter identification. Judging the operation state of the permanent magnet synchronous motor to be subjected to inductance parameter identification; according to the judgment result of the operation state of the permanent magnet synchronous motor to be subjected to inductance parameter identification, the inductance parameters of the permanent magnet synchronous motor in different operation states are identified in different modes, and an identification result is obtained. According to the method, the accuracy and robustness of the parameter identification process of the permanent magnet synchronous motor can be remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet synchronous motor parameter identification, and in particular to an inductance parameter identification method of a permanent magnet synchronous motor based on operating state correction. Background Art

[0002] With the rapid growth of social economy and the development of energy-saving society, the demand for the development and application of high-efficiency and energy-saving motors is getting higher and higher. Permanent magnet synchronous motor (PMSM) uses permanent magnets instead of excitation windings, simplifies the structure of the motor, has high power factor, reliability and small loss, and is widely used in various drive systems such as electric vehicles, robots, and high-end CNC machine tools. Permanent magnet synchronous motor is a complex nonlinear system with the characteristics of multivariable, strong coupling and variable parameters. The high-precision control and high-performance operation of permanent magnet synchronous motors depend on the accurate model of the motor, so it is necessary to obtain the accurate parameters of the motor. However, during the operation of the motor, it is necessary to face complex working conditions and changes in the external environment, such as temperature rise of stator and rotor windings, sudden load changes, etc., which cause the parameters of the motor to change and the motor control performance to deteriorate.

[0003] In order to ensure the good operating performance of the motor and improve the control accuracy, it is necessary to perform real-time online parameter identification of the motor. The common parameter identification method based on the motor voltage equation has the problem of model under-rank, and the accuracy and robustness of identification are poor. The motor parameter identification method based on high-frequency signal injection injects a high-frequency voltage signal into the motor, extracts the corresponding high-frequency response current, and calculates the motor inductance parameters based on the high-frequency model of the permanent magnet synchronous motor. This method realizes the decoupling solution of the motor parameters, and is not affected by the input and output signals and external disturbances, and has good tracking and accuracy. However, the motor needs to face different working conditions in actual operation. The use of a single motor parameter identification method cannot meet the needs of various operating states of the motor, and the identification results have large errors. Summary of the invention

[0004] The present invention provides a method for identifying inductance parameters of a permanent magnet synchronous motor based on operation state correction, so as to solve the technical problem that the existing method for identifying inductance parameters of a permanent magnet synchronous motor has poor accuracy and robustness.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] On the one hand, the present invention provides a method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction, and the method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction includes:

[0007] According to the rotation speed and temperature of the permanent magnet synchronous motor for which inductance parameter identification is to be performed, the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed is judged;

[0008] According to the determination result of the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed, the inductance parameters of the permanent magnet synchronous motor under different operating states are identified in different ways to obtain identification results.

[0009] Further, judging the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed according to the rotation speed and temperature of the permanent magnet synchronous motor for which inductance parameter identification is to be performed includes:

[0010] If the permanent magnet synchronous motor for which inductance parameter identification is currently being performed has not been started, it is determined that its operating state is a state before starting;

[0011] If the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is lower than a preset speed threshold, it is determined that its operating state is a low-speed operating state;

[0012] If the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is not lower than a preset speed threshold, then its operating state is determined to be a high-speed operating state;

[0013] If the temperature of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is higher than a preset temperature threshold, it is determined that its operating state is a heavy load state.

[0014] Furthermore, the inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including:

[0015] If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a pre-starting state, a signal mixed with a DC voltage signal and a high-frequency sinusoidal voltage signal is injected into the motor; the online saturation state of the motor is simulated with the injected DC voltage signal, and then the inductance parameters of the motor are identified according to the injected high-frequency sinusoidal voltage signal using a motor parameter identification method based on high-frequency signal injection to obtain an inductance parameter identification result.

[0016] Furthermore, the inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including:

[0017] If the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is in a low-speed running state, an inductance parameter identification method using multiple frequency signal injection is used to identify the inductance parameter of the motor to obtain an inductance parameter identification result; wherein the inductance parameter identification method using multiple frequency signal injection includes:

[0018] Design the frequency range of the high-frequency voltage signal injected into the motor;

[0019] In the frequency range, a linear variation rule is adopted to sequentially inject high-frequency sinusoidal voltage signals of different frequencies into the motor at fixed time intervals, and after each injection of the high-frequency sinusoidal voltage signal, a motor parameter identification method based on high-frequency signal injection is adopted to identify the inductance parameter of the motor, and an inductance parameter identification result corresponding to the currently injected high-frequency sinusoidal voltage signal is obtained;

[0020] According to the preset weight design principle, the weights of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of each frequency are designed. According to the designed weights, the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies are weightedly fused to obtain the inductance parameter identification results of the motor under low-speed operation.

[0021] Furthermore, the frequency range needs to ensure that it covers the frequency region where the motor inductance parameters are sensitive and does not affect the normal operation of the motor;

[0022] The weight design principle is:

[0023] The more stable the inductance parameter identification results are under different operating conditions, the higher their weight will be;

[0024] When calculating the inductance parameter identification result, the higher the accuracy of the extracted high-frequency response current, the higher the weight of the corresponding inductance parameter identification result;

[0025] The higher the accuracy of the inductance parameter identification result, the higher its weight;

[0026] The greater the inductance parameter identification result is affected by the environment, the lower its weight is;

[0027] The formula for weighted fusion of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies according to the designed weights is expressed as:

[0028]

[0029] in, The result after weighted fusion of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies; L xi represents the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency, i=1,2,…,n, n represents the number of high-frequency sinusoidal voltage signals; ω i Represents the weight of the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency.

[0030] Furthermore, the inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including:

[0031] If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a high-speed operation state, the inductance parameters of the motor are identified by using an inductance parameter identification method using multiple frequency signal injections, and then a frequency correction factor is introduced to correct the inductance parameter identification result obtained by using the inductance parameter identification method using multiple frequency signal injections, so as to obtain the inductance parameter identification result of the motor in a high-speed operation state.

[0032] Furthermore, the expression of the inductance parameter identification result of the motor under high-speed operation is:

[0033]

[0034] Among them, L d (f) represents the d-axis inductance of the motor under high-speed operation; L q (f) represents the q-axis inductance of the motor under high-speed operation; k d (f) represents the frequency correction factor of the d-axis inductance value; k q (f) represents the frequency correction factor of the q-axis inductance value; It represents the d-axis inductance value obtained by the inductance parameter identification method using multiple frequency signal injection; represents the q-axis inductance value obtained by the inductance parameter identification method using multiple frequency signal injection; k d (f) and k q The expression of (f) is as follows:

[0035]

[0036] Where, f represents the operating frequency of the motor; f c,d represents the characteristic frequency of the d-axis inductance; f c,q Indicates the characteristic frequency of the q-axis inductance; α d Represents the attenuation index of the d-axis inductance; α q Indicates the attenuation exponent of the q-axis inductance.

[0037] Furthermore, the inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including:

[0038] If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a heavy load state, the temperature correction coefficient is introduced to correct the voltage equation of the motor in the dq axis reference system. Then, based on the corrected voltage equation, the motor parameter identification method based on high-frequency signal injection is adopted to identify the inductance parameters of the motor, and the inductance parameter identification result of the motor in the heavy load state is obtained.

[0039] Furthermore, the corrected voltage equation is expressed as:

[0040]

[0041] Among them, u d represents the d-axis voltage; u q represents the q-axis voltage; i d represents the d-axis current; i q represents the q-axis current; L d Indicates the d-axis inductance; L q represents the q-axis inductance; t represents time; ω e represents the electrical angular velocity; Represents the rotor flux; R s represents the stator resistance; α represents the temperature correction coefficient of the d-axis inductance; β represents the temperature correction coefficient of the q-axis inductance. The expressions of α and β are as follows:

[0042]

[0043] Where T is the temperature of the motor; m is the degree of the polynomial; a0, a1, a2, …, a m are the fitting parameters corresponding to α; b0, b1, b2, …, b m is the fitting parameter corresponding to β; the parameters a0, a1, …, a are determined by curve fitting the data of the error of the inductance parameter identification result changing with the motor temperature. m and b0,b1,…,b m The value of .

[0044] Furthermore, in the motor parameter identification method based on high-frequency signal injection, when identifying the inductance parameters of the motor, a double second-order generalized integrator is used to filter the high-frequency sinusoidal voltage signal injected into the motor and the induced current signal obtained after the high-frequency sinusoidal voltage signal is injected to obtain the signal of the corresponding frequency, and then the obtained signal of the corresponding frequency is decomposed by the fast Fourier transform algorithm to obtain the amplitude and phase of the high-frequency sinusoidal voltage signal injected into the motor and the corresponding induced current signal.

[0045] On the other hand, the present invention further provides an electronic device, comprising a processor and a memory; wherein the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the above method.

[0046] In yet another aspect, the present invention further provides a computer-readable storage medium, wherein at least one instruction is stored in the storage medium, and the instruction is loaded and executed by a processor to implement the above method.

[0047] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0048] The present invention divides the motor operation state into four conditions: before starting, low-speed operation, high-speed operation and heavy load. The inductance parameter identification method based on high-frequency signal injection is adopted to correct the inductance parameter identification process according to the different operation states of the motor. Thereby, the robustness of the permanent magnet synchronous motor parameter identification process is significantly improved. The system's ability to resist external interference is improved. In addition, in order to further improve the identification accuracy, the present invention adopts a dual second-order generalized integrator instead of a traditional bandpass filter to filter high-frequency signals, and uses a fast Fourier transform to process high-frequency signals to obtain accurate high-frequency responses, thereby further improving the identification accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 It is a schematic diagram of the execution flow of the method for identifying the inductance parameters of a permanent magnet synchronous motor based on operating state correction provided by an embodiment of the present invention;

[0051] Figure 2 Schematic diagram of the implementation principle of the method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction provided by an embodiment of the present invention;

[0052] Figure 3 It is a flow chart of the permanent magnet synchronous motor inductance parameter identification method based on operating state correction provided by an embodiment of the present invention for identifying the inductance parameter of the permanent magnet synchronous motor under different operating states;

[0053] Figure 4 It is a system block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0055] First of all, it should be noted that in the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplarily" is intended to present the concept in a concrete way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0056] First embodiment

[0057] In view of the problem that the inductance parameter identification of the permanent magnet synchronous motor in different operating states cannot be realized in the prior art, this embodiment provides a permanent magnet synchronous motor inductance parameter identification method based on operating state correction, which can be implemented by an electronic device. The execution process of the method is as follows: Figure 1 As shown, the following steps are included:

[0058] S1, judging the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed according to the rotation speed and temperature of the permanent magnet synchronous motor for which inductance parameter identification is to be performed;

[0059] Specifically, in this embodiment, if the permanent magnet synchronous motor for which inductance parameter identification is currently being performed has not been started, its operating state is determined to be the pre-start state; the motor speed is measured by a speed sensor to determine whether the motor is in a low-speed or high-speed operating state, and if the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is lower than a preset speed threshold, its operating state is determined to be a low-speed operating state; if the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is not lower than a preset speed threshold, its operating state is determined to be a high-speed operating state; the temperature sensor is used to detect whether the motor is in a heavy-load state, and if the temperature of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is higher than a preset temperature threshold, its operating state is determined to be a heavy-load state. Among them, the speed threshold and the temperature threshold can be set according to field experience, and this embodiment does not specifically limit this.

[0060] S2, according to the determination result of the operating state of the permanent magnet synchronous motor for which the inductance parameter identification is to be performed, the inductance parameters of the permanent magnet synchronous motor under different operating states are identified in different ways to obtain the identification result;

[0061] Specifically, this embodiment adopts an inductance parameter identification method based on high-frequency signal injection, and corrects the inductance parameter identification process according to different operating states of the motor. The specific principle is as follows: Figure 2 The inductance parameter identification process for different operating state corrections is shown in Figure 3 Among them, the motor parameter identification method based on high-frequency signal injection identifies the inductance parameters according to the high-frequency impedance model of PMSM. The specific identification process is as follows:

[0062] The voltage equation of PMSM in the dq axis reference system is:

[0063]

[0064] Among them, u d 、i d and L d are d-axis voltage, current and inductance respectively; u q 、i qand L q They are q-axis voltage, current and inductance respectively; is the rotor flux; ω e is the electrical angular velocity; t is the time; R s is the stator resistance;

[0065] The injected high frequency signal is expressed as:

[0066] u xh =U xh sin(ω x t+θ xu )x=d,q (2)

[0067] Among them, u dh is the high-frequency voltage signal injected into the d-axis; u qh is the high-frequency voltage signal injected into the q-axis; U dh is the amplitude of the high-frequency voltage signal injected into the d-axis; U qh is the amplitude of the high-frequency voltage signal injected into the q-axis; θ du is the phase of the high-frequency voltage signal injected into the d-axis; θ qu is the phase of the high-frequency voltage signal injected into the q-axis; ω d is the frequency of the high-frequency voltage signal injected into the d-axis; ω q is the frequency of the high-frequency voltage signal injected into the q-axis;

[0068] Substituting into formula (1) we can get:

[0069]

[0070] Among them, I dh is the amplitude of the d-axis high-frequency current response; I qh is the amplitude of the q-axis high-frequency current response; θ di is the phase of the d-axis high-frequency current response; θ qi is the phase of the q-axis high-frequency current response;

[0071] According to the PMSM high-frequency impedance model, we can get:

[0072]

[0073] Then the calculated inductance parameters are:

[0074]

[0075] Among them, L d is the inductance of the d-axis; L q is the inductance of the q-axis.

[0076] Based on the above, the inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways, and the process of obtaining the identification results is as follows:

[0077] 1. If the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is in the pre-starting state, a signal injection method that mixes DC and high-frequency sinusoidal signals is used to identify the inductance parameters for motor startup control. The injected DC signal is used to simulate the online saturation state of the motor to improve the accuracy of motor parameter identification; the injected high-frequency sinusoidal signal is used for motor parameter identification. According to the RL model of the motor, the DC response and the high-frequency sinusoidal response are decoupled from each other, so the inductance parameters can be obtained according to the PMSM high-frequency impedance model, as shown in formula (5).

[0078] 2. If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a low-speed operation state, the inductance parameter identification method of multiple frequency signal injection is adopted. The injected signal frequency needs to ensure that it covers the frequency area where the motor inductance parameters are sensitive and does not affect the normal operation of the motor, so there is an optimal problem. In addition, due to changes in the motor operating environment, the optimal injection frequency is often not fixed. The specific identification process is as follows:

[0079] Under the condition of ensuring the accuracy of the extracted signal and reducing the impact on the motor operation state, the frequency range of the injected high-frequency signal is designed. The high-frequency sine wave signal is injected at a fixed time interval using a linear change rule, and the high-frequency response of the motor is collected respectively. The inductance identification results under different frequency signal injections are calculated according to formula (5): L x1 ,L x2 ,…,L xn ; After obtaining the inductance identification results under different frequency signal injections, the weighted fusion method is used to optimize the identification results. Among them, the weight design needs to consider the following aspects: (1) According to the stability of the identification results, if they remain relatively stable under different motor states, a higher weight should be given; (2) According to the accuracy of the extracted high-frequency response, the identification results with higher high-frequency signal accuracy should be given a higher weight; (3) According to the accuracy of the identification results, the identification results with higher accuracy are given a greater weight; (4) According to the conditions and changes of the experimental environment, the identification results that are more affected by the environment should have their weights reduced. Based on the above considerations, the weight factors of each identification result are designed to be ω1, ω2,…, ω n Then the comprehensive identification results can get the inductance parameters as follows:

[0080]

[0081] in, The result after weighted fusion of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies; L xirepresents the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency, i=1,2,…,n, n represents the number of high-frequency sinusoidal voltage signals; ω i Represents the weight of the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency.

[0082] 3. If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a high-speed operation state, the electromagnetic state of the motor will change, increasing the coupling degree between the dq axes, so further consideration is needed. In this regard, this embodiment proposes a method for identifying the inductance parameters of a motor running at high speed based on low-speed inductance correction. This method directly makes corrections based on the results of the motor's low-speed identification, without the need to introduce other parameter identification methods, and makes up for the problem of decreased identification accuracy of the high-frequency signal injection method when the motor is running at high speed, thereby simplifying the parameter identification process and improving the accuracy of the identification results. The specific implementation process is as follows:

[0083] Considering that when the motor is running at high speed, the cross-coupling term of the dq axis voltage equation in the high-frequency equivalent circuit response cannot be ignored. In order to consider the high-frequency effect, a frequency-related correction factor k is introduced d (f) and k q (f), the inductance is expressed as:

[0084]

[0085] Among them, L d (f) represents the d-axis inductance of the motor under high-speed operation; L q (f) represents the q-axis inductance of the motor under high-speed operation; are the dq axis inductance values ​​at low speed respectively; k d (f), k q (f) is a frequency-dependent correction factor, which is less than 1 and decreases with increasing frequency.

[0086] Therefore, the design correction factor expression is:

[0087]

[0088] Where, f is the operating frequency; f c,d and f c,q are the characteristic frequencies of the d-axis and q-axis inductances, indicating the frequency points at which the inductance value begins to decrease significantly; α d and α q They are the attenuation index of the d-axis and q-axis inductances, respectively, indicating the attenuation rate of the inductance value as the frequency increases. Based on this, the inductance parameter of the motor when running at high speed can be obtained as:

[0089]

[0090] 4. When the motor runs for a long time, the temperature of the motor will increase, which will reduce the residual magnetic induction intensity of the permanent magnet in the rotor and increase the inductance of the AC and DC axes, affecting the control performance of the motor. When the motor is under heavy load, the effect of temperature on inductance is more obvious, and the traditional high-frequency signal injection method does not consider the effect of temperature. Therefore, it is necessary to optimize the inductance parameter identification method when the PMSM is under heavy load. In this regard, this embodiment adds a temperature correction term on the basis of the parameter identification method based on high-frequency signal injection to optimize the inductance identification result. The temperature correction coefficients α and β are introduced as follows:

[0091]

[0092] Where, α is the direct axis inductance L d The correction coefficient, β is the quadrature-axis inductance L q The correction coefficient is , and T is the temperature of the motor. By fitting the data of the change of identification error with temperature, the parameters a0, a1, ..., a m ,b0,b1,…,b m The value of . Where m is the degree of the polynomial;

[0093] Substituting the correction coefficients α and β into the motor expression yields:

[0094]

[0095] The inductance parameters obtained by high-frequency signal injection method are:

[0096]

[0097] Furthermore, the inductor parameter identification method based on high-frequency signal injection needs to obtain the amplitude and phase information of the high-frequency voltage and current when solving. To this end, it is first necessary to filter the voltage signal injected into the dq axis and the obtained induced current signal to obtain the signal of the corresponding frequency, and then decompose the processed signal through the discrete Fourier transform algorithm to obtain the amplitude and phase information of the high-frequency voltage and current:

[0098]

[0099] Usually, a bandpass filter (BPF) is used to extract and process the signal, but the use of BPF will cause filtering delay, thereby reducing the observation accuracy of the control system, resulting in the accumulation of estimation errors and affecting the control performance of the system. Therefore, this embodiment uses a dual second-order generalized integrator (DSOGI) instead of BPF for filtering, thereby improving the signal processing accuracy and thus improving the parameter identification accuracy. Among them, DSOGI includes an inner loop negative feedback regulation, and there is no phase shift in the output signal at the center frequency. At the same time, DSOGI has a strong harmonic reduction capability, so DSOGI can filter specific frequency signals. Its transfer function is:

[0100]

[0101] DSOGI is used to filter the high-frequency signal and accurately extract the signal of the corresponding frequency. Then the fast Fourier transform is used to improve the algorithm processing process to obtain the precise amplitude and phase information of the high-frequency voltage and current.

[0102] In summary, this embodiment provides a method for identifying the inductance parameters of a permanent magnet synchronous motor based on operating state correction. The method divides the motor operating state into four conditions: before starting, low-speed operation, high-speed operation, and heavy load. An inductance parameter identification method based on high-frequency signal injection is used to correct the inductance parameter identification process according to different operating states of the motor. This significantly improves the robustness of the permanent magnet synchronous motor parameter identification process. Improve the system's ability to resist external interference. In addition, in order to further improve the identification accuracy, the method uses a dual second-order generalized integrator instead of a traditional bandpass filter for high-frequency signal filtering, and uses a fast Fourier transform to process the high-frequency signal to obtain an accurate high-frequency response, thereby further improving the identification accuracy.

[0103] Second embodiment

[0104] This embodiment provides an electronic device, such as Figure 4 As shown, the electronic device includes: a processor and a memory; wherein the processor and the memory can be connected via a communication bus; the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method of the first embodiment. In addition, the electronic device may also include a transceiver, the processor and the transceiver can be connected via a communication bus, and the transceiver is used to communicate with other devices.

[0105] Next, combine Figure 4 The following is a detailed introduction to the various components of the electronic device:

[0106] Among them, the processor is the control center of the electronic device, and the electronic device may include multiple processors, each of which may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may be a processor or a general term for multiple processing elements. For example, the processor is one or more central processing units (CPUs), or other general-purpose processors, application specific integrated circuits (ASICs), or one or more integrated circuits configured to implement an embodiment of the present invention, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor may execute various functions of the electronic device by running or executing software programs stored in the memory and calling data stored in the memory.

[0107] In a specific implementation, as an embodiment, the processor may include one or more CPUs, such as Figure 4 The CPU0 and CPU1 shown in the figure are, of course, only exemplary.

[0108] The memory is used to store the software program for executing the solution of the present invention, and the execution is controlled by the processor. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0109] Optionally, the memory may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may be integrated with the processor or exist independently and accessed through the interface circuit ( Figure 4 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0110] The transceiver may include a receiver and a transmitter ( Figure 4 The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function. The transceiver can be integrated with the processor or exist independently and communicate with the electronic device through the interface circuit ( Figure 4 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0111] In addition, it should be noted that Figure 4 The structure of the electronic device shown in the figure does not constitute a limitation on the device, and the actual device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. In addition, the technical effects achieved by the electronic device when executing the method of the first embodiment above can refer to the technical effects described in the first embodiment above, so they are not repeated here.

[0112] Third embodiment

[0113] This embodiment provides a computer-readable storage medium, which stores at least one instruction, and the instruction is loaded and executed by a processor to implement the method of the first embodiment. The computer-readable storage medium may be a ROM, a random access memory, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. The instructions stored therein may be loaded by a processor in a terminal to execute the method.

[0114] In addition, it should be noted that the present invention can be provided as a method, an apparatus or a computer program product. Therefore, the embodiment of the present invention can be in the form of a full or partial hardware embodiment, a full or partial software embodiment or an embodiment combining software and hardware. Moreover, when implemented using software, the embodiment of the present invention can be in the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program codes. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center containing one or more available media sets. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium. The semiconductor medium may be a solid state hard disk.

[0115] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0117] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements. In addition, the term "and / or" is only an association relationship describing the associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone, wherein A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding. "At least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can be represented by: a, b, c, ab, ac, bc or abc, where a, b, c can be single or plural.

[0118] In addition, it can be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0119] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0120] In several embodiments provided by the present invention, it should be understood that the disclosed equipment, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of functional modules / units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0121] If the method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0122] Finally, it should be noted that the above is only a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for ordinary technicians in this technical field, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction, characterized in that: The permanent magnet synchronous motor inductance parameter identification method based on operating state correction includes: According to the rotation speed and temperature of the permanent magnet synchronous motor for which inductance parameter identification is to be performed, the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed is judged; According to the determination result of the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed, the inductance parameters of the permanent magnet synchronous motor under different operating states are identified in different ways to obtain identification results.

2. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 1, characterized in that: The step of determining the operating state of the permanent magnet synchronous motor for which inductance parameter identification is to be performed according to the rotation speed and temperature of the permanent magnet synchronous motor for which inductance parameter identification is to be performed includes: If the permanent magnet synchronous motor for which inductance parameter identification is currently being performed has not been started, it is determined that its operating state is a state before starting; If the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is lower than a preset speed threshold, it is determined that its operating state is a low-speed operating state; If the speed of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is not lower than a preset speed threshold, then its operating state is determined to be a high-speed operating state; If the temperature of the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is higher than a preset temperature threshold, it is determined that the operating state of the permanent magnet synchronous motor is a heavy load state.

3. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 2, characterized in that: The inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including: If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a pre-starting state, a signal mixed with a DC voltage signal and a high-frequency sinusoidal voltage signal is injected into the motor; the online saturation state of the motor is simulated with the injected DC voltage signal, and then the inductance parameters of the motor are identified according to the injected high-frequency sinusoidal voltage signal using a motor parameter identification method based on high-frequency signal injection to obtain an inductance parameter identification result.

4. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 2, characterized in that: The inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including: If the permanent magnet synchronous motor for which inductance parameter identification is currently being performed is in a low-speed running state, an inductance parameter identification method using multiple frequency signal injection is used to identify the inductance parameter of the motor to obtain an inductance parameter identification result; wherein the inductance parameter identification method using multiple frequency signal injection includes: Design the frequency range of the high-frequency voltage signal injected into the motor; In the frequency range, a linear variation rule is adopted to sequentially inject high-frequency sinusoidal voltage signals of different frequencies into the motor at fixed time intervals, and after each injection of the high-frequency sinusoidal voltage signal, a motor parameter identification method based on high-frequency signal injection is adopted to identify the inductance parameter of the motor, and an inductance parameter identification result corresponding to the currently injected high-frequency sinusoidal voltage signal is obtained; According to the preset weight design principle, the weights of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of each frequency are designed. According to the designed weights, the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies are weightedly fused to obtain the inductance parameter identification results of the motor under low-speed operation.

5. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 4, characterized in that: The frequency range needs to ensure that it covers the frequency region where the motor inductance parameters are sensitive and does not affect the normal operation of the motor; The weight design principle is: The more stable the inductance parameter identification results are under different operating conditions, the higher their weight will be; When calculating the inductance parameter identification result, the higher the accuracy of the extracted high-frequency response current, the higher the weight of the corresponding inductance parameter identification result; The higher the accuracy of the inductance parameter identification result, the higher its weight; The greater the inductance parameter identification result is affected by the environment, the lower its weight is; The formula for weighted fusion of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies according to the designed weights is expressed as: in, The result after weighted fusion of the inductance parameter identification results corresponding to the high-frequency sinusoidal voltage signals of different frequencies; L xi represents the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency, i=1,2,…,n, n represents the number of high-frequency sinusoidal voltage signals; ω i Represents the weight of the inductance parameter identification result corresponding to the high-frequency sinusoidal voltage signal of the i-th frequency.

6. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 4, characterized in that: The inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including: If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a high-speed operation state, the inductance parameters of the motor are identified by using an inductance parameter identification method using multiple frequency signal injections, and then a frequency correction factor is introduced to correct the inductance parameter identification result obtained by using the inductance parameter identification method using multiple frequency signal injections, so as to obtain the inductance parameter identification result of the motor in a high-speed operation state.

7. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 6, characterized in that: The expression of the inductance parameter identification result of the motor under high-speed operation is: Among them, L d (f) represents the d-axis inductance of the motor under high-speed operation; L q (f) represents the q-axis inductance of the motor under high-speed operation; k d (f) represents the frequency correction factor of the d-axis inductance value; k q (f) represents the frequency correction factor of the q-axis inductance; It represents the d-axis inductance value obtained by the inductance parameter identification method using multiple frequency signal injection; represents the q-axis inductance value obtained by the inductance parameter identification method using multiple frequency signal injection; k d (f) and k q The expression of (f) is as follows: Where, f represents the operating frequency of the motor; f c,d represents the characteristic frequency of the d-axis inductance; f c,q Indicates the characteristic frequency of the q-axis inductance; α d Represents the attenuation index of the d-axis inductance; α q Indicates the attenuation exponent of the q-axis inductance.

8. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 2, characterized in that: The inductance parameters of the permanent magnet synchronous motor under different operating conditions are identified in different ways to obtain identification results, including: If the permanent magnet synchronous motor whose inductance parameters are to be identified is in a heavy load state, the temperature correction coefficient is introduced to correct the voltage equation of the motor in the dq axis reference system. Then, based on the corrected voltage equation, the motor parameter identification method based on high-frequency signal injection is adopted to identify the inductance parameters of the motor, and the inductance parameter identification result of the motor in the heavy load state is obtained.

9. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to claim 8, characterized in that: The corrected voltage equation is: Among them, u d represents the d-axis voltage; u q represents the q-axis voltage; i d represents the d-axis current; i q represents the q-axis current; L d Indicates the d-axis inductance; L q represents the q-axis inductance; t represents time; ω e represents the electrical angular velocity; Represents the rotor flux; R s represents the stator resistance; α represents the temperature correction coefficient of the d-axis inductance; β represents the temperature correction coefficient of the q-axis inductance. The expressions of α and β are as follows: Where T is the temperature of the motor; m is the degree of the polynomial; a0, a1, a2, …, a m are the fitting parameters corresponding to α; b0, b1, b2, …, b m is the fitting parameter corresponding to β; the parameters a0, a1, …, a are determined by curve fitting the data of the error of the inductance parameter identification result changing with the motor temperature. m and b0,b1,…,b m The value of .

10. The method for identifying inductance parameters of a permanent magnet synchronous motor based on operating state correction according to any one of claims 3 to 9, characterized in that: In the motor parameter identification method based on high-frequency signal injection, when identifying the inductance parameters of the motor, a double second-order generalized integrator is used to filter the high-frequency sinusoidal voltage signal injected into the motor and the induced current signal obtained after the high-frequency sinusoidal voltage signal is injected to obtain the signal of the corresponding frequency, and then the obtained signal of the corresponding frequency is decomposed by the fast Fourier transform algorithm to obtain the high-frequency sinusoidal voltage signal injected into the motor and the amplitude and phase of the corresponding induced current signal.

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