A method, system, device and storage medium for calculating the angle of a motor rotor

Abstract

An embodiment of the present invention discloses a method, system, device, and storage medium for calculating the rotor angle of a motor, including: obtaining a first current and a second current of any two drive lines of a three-phase brushless motor; performing a coordinate transformation on the first current and the second current to obtain a d-axis current and a q-axis current in the dq coordinate system; extracting high-frequency currents from the d-axis current and the q-axis current to obtain a d-axis high-frequency current and a q-axis high-frequency current; multiplying the q-axis high-frequency current by itself to obtain a first high-frequency current, and multiplying the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current; extracting the direct current in the first high-frequency current and determining the positive and negative values of the second high-frequency current; multiplying the positive and negative values by the direct current to obtain a final direct current, and obtaining the rotor angle of the three-phase brushless motor based on the final direct current. It solves the technical problem that for motors with non-obvious salient poles, it is impossible to estimate the rotor angle of the motor using the high-frequency injection method at present.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of motors, and in particular, to a method, system, device, and storage medium for calculating the rotor angle of a motor. Background Art

[0002] Currently, when estimating the rotor angle of a three-phase brushless motor, the high-frequency injection method is usually adopted. The high-frequency injection method is a software algorithm that can accurately estimate the rotor angle of the motor when the motor is in a stationary state or a low-speed state, and high-precision motor control can be achieved without the aid of an angle sensor during this process.

[0003] In the prior art, the process of the high-frequency injection method is as follows: During the operation of the motor, a group of high-frequency sine wave voltage signals are calculated and "injected" (superimposed output) onto the motor through software. Then, the software analyzes the characteristics of the feedback high-frequency sine wave current to deduce the angle where the rotor of the motor is located for precise control. However, for some motors with non-obvious salient polarities (the inductance change of the motor coil is not obvious), when using the high-frequency injection method, high-frequency sine wave voltage signals with a relatively high frequency need to be injected. However, limited by the SVPWM modulation technology, the frequency of the high-frequency sine wave voltage signal cannot be too high, otherwise the feedback high-frequency sine wave current will be distorted (not a sine wave). Then, when the software analyzes the characteristics of the high-frequency sine wave current, the required information cannot be calculated, resulting in the inability to estimate the rotor angle of the motor.

[0004] In summary, in the prior art, for motors with non-obvious salient polarities, there is a technical problem that the high-frequency injection method cannot be used to estimate the rotor angle of the motor. Summary of the Invention

[0005] Embodiments of the present invention provide a method, system, device, and storage medium for calculating the rotor angle of a motor, which solve the technical problem in the prior art that for motors with non-obvious salient polarities, the high-frequency injection method cannot be used to estimate the rotor angle of the motor.

[0006] In a first aspect, embodiments of the present invention provide a method for calculating the rotor angle of a motor, including the following steps:

[0007] Obtain the first current and the second current of any two drive lines of a three-phase brushless motor;

[0008] Perform a coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system;

[0009] Extract the high-frequency current from the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current;

[0010] Multiply the q-axis high-frequency current by itself to obtain a first high-frequency current, and multiply the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current;

[0011] Extract the direct current in the first high-frequency current and determine the positive and negative values of the second high-frequency current;

[0012] Multiply the positive and negative values by the direct current to obtain a final direct current, and obtain the rotor angle of the three-phase brushless motor based on the final direct current.

[0013] Preferably, the specific process of performing coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system is as follows:

[0014] Perform Clarke transformation on the first current and the second current to obtain the α-axis current and the β-axis current in the αβ coordinate system;

[0015] Perform Park transformation on the α-axis current and the β-axis current to obtain the d-axis current and the q-axis current in the dq coordinate system.

[0016] Preferably, the specific process of obtaining the rotor angle of the three-phase brushless motor based on the final direct current is as follows:

[0017] Perform speed regulation and angle integration on the final direct current to obtain the rotor angle of the three-phase brushless motor.

[0018] Preferably, a band-pass filter is used to extract the high-frequency currents in the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current.

[0019] Preferably, a low-pass filter is used to extract the direct current in the first high-frequency current.

[0020] In a second aspect, an embodiment of the present invention provides a device for calculating the rotor angle of a motor, including:

[0021] A current acquisition module for acquiring a first current and a second current of any two drive lines of a three-phase brushless motor;

[0022] A coordinate conversion module for performing coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system;

[0023] A high-frequency current extraction module for extracting the high-frequency currents in the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current;

[0024] A multiplier module for multiplying the q-axis high-frequency current by itself to obtain a first high-frequency current, and multiplying the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current;

[0025] A DC extraction module for extracting the DC current in the first high-frequency current and determining the positive and negative values of the second high-frequency current;

[0026] A rotor angle calculation module for multiplying the positive and negative values by the DC current to obtain a final DC current, and obtaining the rotor angle of the three-phase brushless motor based on the final DC current.

[0027] Preferably, the coordinate transformation module includes:

[0028] A Clarke transformation sub-module for performing Clarke transformation on the first current and the second current to obtain the α-axis current and the β-axis current in the αβ coordinate system;

[0029] A Park transformation sub-module for performing Park transformation on the α-axis current and the β-axis current to obtain the d-axis current and the q-axis current in the dq coordinate system.

[0030] Preferably, the specific process for the rotor angle calculation module to obtain the rotor angle of the three-phase brushless motor based on the final DC current is as follows:

[0031] Performing speed regulation and angle integration on the final DC current to obtain the rotor angle of the three-phase brushless motor.

[0032] Preferably, the high-frequency current extraction module is specifically configured to extract the high-frequency currents in the d-axis current and the q-axis current by using a band-pass filter to obtain the d-axis high-frequency current and the q-axis high-frequency current.

[0033] Preferably, the DC extraction module is specifically configured to extract the DC current in the first high-frequency current by using a low-pass filter.

[0034] In a third aspect, an embodiment of the present invention provides a motor rotor angle calculation device, including a processor and a memory; the memory is used to store a computer program and transmit the computer program to the processor; the processor is used to execute the motor rotor angle calculation method as described in the first aspect according to the instructions in the computer program.

[0035] In a fourth aspect, an embodiment of the present invention provides a storage medium storing computer-executable instructions, and the computer-executable instructions are used to execute the motor rotor angle calculation method as described in the first aspect when executed by a computer processor.

[0036] As described above, the embodiments of the present invention provide a method, a system, a device, and a storage medium for calculating the rotor angle of a motor. The method includes: obtaining a first current and a second current of any two drive lines of a three-phase brushless motor; performing a coordinate transformation on the first current and the second current to obtain a d-axis current and a q-axis current in the dq coordinate system; extracting high-frequency currents from the d-axis current and the q-axis current to obtain a d-axis high-frequency current and a q-axis high-frequency current; multiplying the q-axis high-frequency current by itself to obtain a first high-frequency current, and multiplying the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current; extracting the direct current in the first high-frequency current, and determining the positive and negative values of the second high-frequency current; multiplying the positive and negative values by the direct current to obtain a final direct current, and obtaining the rotor angle of the three-phase brushless motor based on the final direct current. In the embodiments of the present invention, by multiplying the d-axis high-frequency current by itself to obtain a first high-frequency current, extracting the direct current in the first high-frequency current, multiplying the direct current by the positive and negative values of the second high-frequency current to obtain a final direct current, and obtaining the rotor angle of the three-phase brushless motor according to the final direct current. Thus, even when the injection frequency is too high and the q-axis high-frequency current is severely distorted, the rotor angle of the three-phase brushless motor can be accurately calculated, solving the technical problem in the prior art that for a motor with an inconspicuous salient polarity, it is impossible to estimate the rotor angle of the motor using the high-frequency injection method. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 FIG. is a demodulation schematic diagram of the traditional high-frequency injection method provided by the embodiments of the present invention.

[0038] Figure 2 FIG. is a flowchart of a method for calculating the rotor angle of a motor provided by the embodiments of the present invention.

[0039] Figure 3 FIG. is a schematic diagram of the principle of transforming the first current and the second current provided by the embodiments of the present invention.

[0040] Figure 4 FIG. is a demodulation schematic diagram of the high-frequency injection method provided by the embodiments of the present invention.

[0041] Figure 5 FIG. is a schematic structural diagram of a device for calculating the rotor angle of a motor provided by the embodiments of the present invention.

[0042] Figure 6 FIG. is a schematic structural diagram of a device for calculating the rotor angle of a motor provided by the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The following description and drawings fully illustrate specific embodiments of the present application, enabling those skilled in the art to practice them. The embodiments merely represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations can vary. Parts and features of some embodiments can be included in or replace parts and features of other embodiments. The scope of the embodiments of the present application includes the entire scope of the claims and all available equivalents of the claims. Herein, each embodiment can be individually or collectively represented by the term "invention" for convenience only, and if in fact more than one invention is disclosed, it is not intended to automatically limit the scope of the application to any single invention or inventive concept. Herein, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method or device comprising a series of elements not only includes those elements but also other elements not explicitly listed. The embodiments herein are described in a progressive manner, with each embodiment highlighting the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the structures, products, etc. disclosed in the embodiments, since they correspond to the parts disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0044] Figure 1 It is a schematic diagram of demodulation by the traditional high-frequency injection method. Among them, is the high-frequency current returned to the processor after injecting a high-frequency sinusoidal voltage. In Figure 1 we multiply by so as to decompose into the DC current and AC current in That is, contains high-frequency information. After combining it with we get where the first part is the DC component and the second part is the high-frequency component with cosine variation. Then, the high-frequency component is filtered out by a low-pass filter, and the DC component is retained to obtain c where k is the amplification coefficient incorporated in the low-pass filter, U c is the peak value of the injected high-frequency sinusoidal voltage, ω h is the average inductance of the motor coil under the high-frequency sinusoidal voltage, ΔL h is the difference between the maximum inductance and the minimum inductance, and Δθ r is the rotor angle calculation error value.

[0045] which contains the rotor angle error sin(2Δθ r ), and other quantities are constants, which do not affect the subsequent calculations. Subsequently, the rotational speed and the rotor angle are calculated using the speed PI operation. However, the problem with traditional demodulation methods is that if the injected voltage frequency is too high, the high-frequency signal waveform will be severely distorted and deviate significantly from If it is multiplied by the given then it cannot meet the requirements of the formula, and the subsequent calculation of the rotor angle cannot be accurately achieved.

[0046] Embodiment 1

[0047] As Figure 2 shown, Figure 2 is a flowchart of a method for calculating the rotor angle of a motor provided by an embodiment of the present invention. The method for calculating the rotor angle of a motor provided in the embodiments of the present application can be executed by a motor rotor angle calculation device. The motor rotor angle calculation device can be implemented in software and / or hardware. The motor rotor angle calculation device can be composed of two or more physical entities or can be composed of one physical entity. The method includes the following steps:

[0048] Step 101: Obtain the first current and the second current of any two drive lines of a three-phase brushless motor.

[0049] In this embodiment, after injecting a high-frequency sinusoidal voltage into the three-phase brushless motor, the first current i a and the second current i b on any two drive lines of the three-phase brushless motor are obtained. Since the vector sum of the currents on the three drive lines is 0, after obtaining the first current and the second current, the current on the third drive line of the three-phase brushless motor can be calculated according to the first current and the second current. In one embodiment, a clamp meter can be used to measure the current on the drive line of the three-phase brushless motor. It can be understood that in this embodiment, the method for measuring the current on the drive line of the three-phase brushless motor can be set according to actual needs and is not specifically limited in this embodiment.

[0050] Step 102: Perform a coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system.

[0051] After obtaining the first current i a and the second current i b , for the convenience of subsequent calculations, it is necessary to perform a coordinate transformation on the first current i a and the second current i b , and convert the first current i aand the second current i b are converted into the d-axis current and the q-axis current in the dq coordinate system.

[0052] In one embodiment, the coordinate transformation of the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system is specifically executed by steps 1021-step 1022:

[0053] Step 1021: For the first current i a and the second current i b perform a Clarke transformation to obtain the α-axis current i α and the β-axis current i β .

[0054] The Clarke transformation is used to convert the time-domain components of a three-phase system (in the abc coordinate system) into two components in an orthogonal stationary coordinate system (αβ coordinate system). Therefore, in this embodiment, the first current i a and the second current i b in the abc coordinate system are converted into the α-axis current i α and the β-axis current i β in the αβ coordinate system.

[0055] Step 1022: For the α-axis current i α and the β-axis current i β perform a Park transformation to obtain the d-axis current and the q-axis current in the dq coordinate system.

[0056] The Park transformation is used to convert two components in the αβ coordinate system into an orthogonal rotating coordinate system (dq coordinate system). Therefore, in this embodiment, the α-axis current i α and the β-axis current i β in the αβ coordinate system are converted into the d-axis current and the q-axis current It should be further noted that the rotor angle of the three-phase brushless motor needs to be used for calculation during the Park transformation In one embodiment, the rotor angle obtained from the previous calculation can be used during the transformation process of the Park transformation.

[0057] In this embodiment, as Figure 3 shown, the first current i a and the second current i b are subjected to Clarke transformation and Park transformation to obtain the d-axis current and the q-axis current By implementing two consecutive transformations, the alternating current can be converted into a direct current signal, thereby simplifying the calculation, and the d-axis current and the q-axis current contains injected high-frequency sine information and the rotor angle error Δθ r .

[0058] Step 103: Extract the high-frequency currents in the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current.

[0059] Since the d-axis current and the q-axis current not only contain the injected high-frequency signals but also include the low-frequency signals during the operation of the three-phase brushless motor. Therefore, in this embodiment, it is necessary to extract the high-frequency currents required for subsequent calculations from the d-axis current and the q-axis current respectively, to obtain the d-axis high-frequency current and the q-axis high-frequency current

[0060] In one embodiment, a band-pass filter is used to extract the high-frequency currents in the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current.

[0061] To extract the high-frequency currents in the d-axis current and the q-axis current , a band-pass filter can be used to extract the high-frequency currents. As Figure 4 shown, by presetting the frequency range of the high-frequency current in the band-pass filter, only the current signals within this frequency range are allowed to pass through the band-pass filter, and the current signals in other frequency ranges are filtered out, so as to obtain the high-frequency current within the preset frequency range.

[0062] In this embodiment, the formulas for the d-axis high-frequency current and the q-axis high-frequency current extracted by the band-pass filter are as follows respectively:

[0063]

[0064]

[0065] Wherein, U c is the peak value of the injected high-frequency sine voltage, ω c is the angular frequency of the injected high-frequency sine voltage, L h is the average inductance of the motor coil under the high-frequency sine voltage (i.e., equal to the average value of the d-axis inductance L d and the q-axis inductance L q : L h =(L d +L q ) / 2), ΔL his the difference between the maximum inductance and the minimum inductance (i.e., the q-axis inductance L q minus the d-axis inductance L d : L q -L d ), and Δθ r is the rotor angle calculation error value.

[0066] Step 104: Multiply the q-axis high-frequency current by itself to obtain the first high-frequency current, and multiply the d-axis high-frequency current by the q-axis high-frequency current to obtain the second high-frequency current.

[0067] After obtaining the d-axis high-frequency current and the q-axis high-frequency current , multiply the q-axis high-frequency current by itself to obtain the first high-frequency current Even if the q-axis high-frequency current is severely distorted, due to the multiplication of the q-axis high-frequency current by itself, the final calculation result can still meet the requirements of this formula, enabling accurate subsequent angle estimation.

[0068] Multiply the d-axis high-frequency current and the q-axis high-frequency current to obtain the second high-frequency current Simplify the second high-frequency current to obtain Since L h and ΔL h are both positive integers, G is a number that is always positive, that is, the positive and negative values of the second high-frequency current reflect the positive and negative signs of sin(2Δθ r ).

[0069] Step 105: Extract the DC current from the first high-frequency current and determine the positive and negative values of the second high-frequency current.

[0070] After obtaining the first high-frequency current , it is necessary to filter out the high-frequency components from the first high-frequency DC current and retain the DC component for subsequent calculation of the rotor angle. In one embodiment, a low-pass filter is used to extract the DC current from the first high-frequency current, and the high-frequency components in the first high-frequency current are filtered out through the low-pass filter to obtain the DC current The specific formula is:

[0071]

[0072] It can be seen that although it includes sin(2Δθ r ), it lacks sin(2Δθ rPositive and negative values will cause the subsequent speed PI link to be unable to correct, so it is necessary to obtain the sign of sin(2Δθ from the second high-frequency current r . Since the sign of the second high-frequency current is the sign of sin(2Δθ r ), in this embodiment, it is only necessary to determine the sign of the second high-frequency current .

[0073] Step 106: Multiply the positive and negative value by the DC current to obtain the final DC current, and obtain the rotor angle of the three-phase brushless motor based on the final DC current.

[0074] After determining the sign of the second high-frequency current , multiply the DC current by the positive and negative value to obtain the final DC current . The formula is as follows:[[]]

[0075] Simplified to

[0076] After obtaining the final DC current , the rotor angle of the three-phase brushless motor can be solved according to the final DC current .

[0077] Based on the above embodiment, the specific process of obtaining the rotor angle of the three-phase brushless motor based on the final DC current is as follows:[[]]

[0078] Perform speed regulation and angle integration on the final DC current to obtain the rotor angle of the three-phase brushless motor.

[0079] After obtaining the final DC current , perform speed PI on the final DC current to obtain the rotor speed . Then perform angle integration to accurately calculate the rotor angle of the three-phase brushless motor.

[0080] As described above, the embodiments of the present invention provide a method, a system, a device, and a storage medium for calculating the rotor angle of a motor. The method includes: obtaining a first current and a second current of any two drive lines of a three-phase brushless motor; performing a coordinate transformation on the first current and the second current to obtain a d-axis current and a q-axis current in the dq coordinate system; extracting high-frequency currents from the d-axis current and the q-axis current to obtain a d-axis high-frequency current and a q-axis high-frequency current; multiplying the q-axis high-frequency current by itself to obtain a first high-frequency current, and multiplying the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current; extracting the direct current in the first high-frequency current and determining the positive and negative values of the second high-frequency current; multiplying the positive and negative values by the direct current to obtain a final direct current, and obtaining the rotor angle of the three-phase brushless motor based on the final direct current. In the embodiments of the present invention, by multiplying the d-axis high-frequency current by itself to obtain a first high-frequency current, extracting the direct current in the first high-frequency current, multiplying the direct current by the positive and negative values of the second high-frequency current to obtain a final direct current, and obtaining the rotor angle of the three-phase brushless motor according to the final direct current. Thus, even when the injection frequency is too high and the q-axis high-frequency current is severely distorted, the rotor angle of the three-phase brushless motor can be accurately calculated, solving the technical problem in the prior art that for a motor with an unclear salient polarity, it is impossible to estimate the rotor angle of the motor using the high-frequency injection method.

[0081] Embodiment 2

[0082] As Figure 5 shown Figure 5 is a schematic structural diagram of a device for calculating the rotor angle of a motor provided by an embodiment of the present invention, including:

[0083] A current acquisition module 201, configured to obtain a first current and a second current of any two drive lines of a three-phase brushless motor;

[0084] A coordinate conversion module 202, configured to perform a coordinate transformation on the first current and the second current to obtain a d-axis current and a q-axis current in the dq coordinate system;

[0085] A high-frequency current extraction module 203, configured to extract high-frequency currents from the d-axis current and the q-axis current to obtain a d-axis high-frequency current and a q-axis high-frequency current;

[0086] A multiplier module 204, configured to multiply the d-axis high-frequency current by itself to obtain a first high-frequency current, and multiply the d-axis high-frequency current by the q-axis high-frequency current to obtain a second high-frequency current;

[0087] A direct current extraction module 205, configured to extract the direct current in the first high-frequency current and determine the positive and negative values of the second high-frequency current;

[0088] The rotor angle calculation module 206 is configured to multiply positive and negative values by a direct current to obtain a final direct current, and obtain the rotor angle of the three-phase brushless motor based on the final direct current.

[0089] Based on the above embodiments, the coordinate transformation module 202 includes:

[0090] The Clarke transformation sub-module is configured to perform Clarke transformation on the first current and the second current to obtain the α-axis current and the β-axis current in the αβ coordinate system;

[0091] The Park transformation sub-module is configured to perform Park transformation on the α-axis current and the β-axis current to obtain the d-axis current and the q-axis current in the dq coordinate system.

[0092] Based on the above embodiments, the specific process for the rotor angle calculation module 206 to obtain the rotor angle of the three-phase brushless motor based on the final direct current is as follows:

[0093] Perform speed regulation and angle integration on the final direct current to obtain the rotor angle of the three-phase brushless motor.

[0094] Based on the above embodiments, the high-frequency current extraction module 203 is specifically configured to extract high-frequency currents in the d-axis current and the q-axis current by using a band-pass filter to obtain the d-axis high-frequency current and the q-axis high-frequency current.

[0095] Based on the above embodiments, the direct current extraction module 205 is specifically configured to extract the direct current in the first high-frequency current by using a low-pass filter.

[0096] Embodiment III

[0097] As Figure 6 shown, a motor rotor angle calculation device includes a processor 400 and a memory 401;

[0098] The memory 401 is configured to store a computer program 402 and transmit the computer program 402 to the processor;

[0099] The processor 400 is configured to execute the steps in the above-mentioned embodiment of the motor rotor angle calculation method according to the instructions in the computer program 402.

[0100] Exemplarily, the computer program 402 can be divided into one or more modules / units. One or more modules / units are stored in the memory 401 and executed by the processor 400 to complete the present application. One or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 402 in the motor rotor angle calculation device.

[0101] The motor rotor angle calculation device can be a computing device such as a desktop computer, notebook, handheld computer, and cloud server. The motor rotor angle calculation device may include, but is not limited to, a processor 400 and a memory 401. Those skilled in the art can understand that Figure 6 merely examples of the motor rotor angle calculation device, which do not constitute a limitation on the motor rotor angle calculation device, may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, the motor rotor angle calculation device may also include input / output devices, network access devices, buses, etc.

[0102] The so-called processor 400 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0103] The memory 401 may be an internal storage unit of the motor rotor angle calculation device, such as the hard disk or memory of the motor rotor angle calculation device. The memory 401 may also be an external storage device of the motor rotor angle calculation device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the motor rotor angle calculation device. Further, the memory 401 may also include both the internal storage unit and the external storage device of the motor rotor angle calculation device. The memory 401 is used to store computer programs and other programs and data required by the motor rotor angle calculation device. The memory 401 may also be used to temporarily store data that has been output or will be output.

[0104] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described systems, devices, and devices can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0105] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces, and the indirect coupling or communication connection of devices or units can be in electrical, mechanical, or other forms.

[0106] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0107] In addition, each functional unit in various embodiments 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. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0108] If the integrated unit 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, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store computer programs.

[0109] Embodiment 4

[0110] The embodiment of the present invention further provides a storage medium containing computer-executable instructions. The computer-executable instructions are used to execute a method for calculating the angle of a motor rotor when executed by a computer processor. The method includes the following steps:

[0111] Obtain the first current and the second current of any two drive lines of a three-phase brushless motor;

[0112] Perform coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system;

[0113] Extract the high-frequency currents from the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current;

[0114] Multiply the q-axis high-frequency current by itself to obtain the first high-frequency current, and multiply the d-axis high-frequency current by the q-axis high-frequency current to obtain the second high-frequency current;

[0115] Extract the DC current from the first high-frequency current and determine the positive and negative values of the second high-frequency current;

[0116] Multiply the positive and negative values by the DC current to obtain the final DC current, and obtain the rotor angle of the three-phase brushless motor based on the final DC current.

[0117] Note that the above is only the preferred embodiment of the embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the embodiments of the present invention are not limited to the specific embodiments here. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the embodiments of the present invention. Therefore, although the embodiments of the present invention have been described in more detail through the above embodiments, the embodiments of the present invention are not limited to the above embodiments. Without departing from the concept of the embodiments of the present invention, more other equivalent embodiments can be included, and the scope of the embodiments of the present invention is determined by the scope of the appended claims.

Claims

1. A method for calculating the angle of a motor rotor, characterized in that, It includes the following steps: Obtain the first current and the second current of any two drive lines of a three-phase brushless motor; Perform coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system; Extract the high-frequency currents from the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current; Multiply the q-axis high-frequency current by itself to obtain the first high-frequency current, and multiply the d-axis high-frequency current by the q-axis high-frequency current to obtain the second high-frequency current; Extract the direct current in the first high-frequency current and determine the positive and negative values of the second high-frequency current; Multiply the positive and negative values by the direct current to obtain the final direct current, and obtain the rotor angle of the three-phase brushless motor based on the final direct current.

2. The method for calculating the angle of a motor rotor according to claim 1, characterized in that, The specific process of performing coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system is as follows: Perform Clarke transformation on the first current and the second current to obtain the α-axis current and the β-axis current in the αβ coordinate system; Perform Park transformation on the α-axis current and the β-axis current to obtain the d-axis current and the q-axis current in the dq coordinate system.

3. A method for calculating the angle of a motor rotor according to claim 1, characterized in that, The specific process of obtaining the rotor angle of the three-phase brushless motor based on the final direct current is as follows: Perform speed regulation and angle integration on the final direct current to obtain the rotor angle of the three-phase brushless motor.

4. A method for calculating the angle of a motor rotor according to claim 1, characterized in that, Use a band-pass filter to extract the high-frequency currents from the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current.

5. A method for calculating the angle of a motor rotor according to claim 1, characterized in that, Use a low-pass filter to extract the direct current in the first high-frequency current.

6. A device for calculating the angle of an electric motor rotor, characterized in that, It includes: A current acquisition module for obtaining the first current and the second current of any two drive lines of a three-phase brushless motor; A coordinate conversion module for performing coordinate transformation on the first current and the second current to obtain the d-axis current and the q-axis current in the dq coordinate system; A high-frequency current extraction module for extracting the high-frequency currents from the d-axis current and the q-axis current to obtain the d-axis high-frequency current and the q-axis high-frequency current; A multiplier module for multiplying the q-axis high-frequency current by itself to obtain the first high-frequency current, and multiplying the d-axis high-frequency current by the q-axis high-frequency current to obtain the second high-frequency current; A direct current extraction module for extracting the direct current in the first high-frequency current and determining the positive and negative values of the second high-frequency current; A rotor angle calculation module for multiplying the positive and negative values by the direct current to obtain the final direct current, and obtaining the rotor angle of the three-phase brushless motor based on the final direct current.

7. The motor rotor angle calculation device according to claim 6, characterized in that, The coordinate conversion module includes: A Clarke transformation sub-module for performing Clarke transformation on the first current and the second current to obtain the α-axis current and the β-axis current in the αβ coordinate system; A Park transformation sub-module for performing Park transformation on the α-axis current and the β-axis current to obtain the d-axis current and the q-axis current in the dq coordinate system.

8. The motor rotor angle calculation device according to claim 6, wherein, The specific process by which the rotor angle calculation module is used to obtain the rotor angle of the three-phase brushless motor based on the final direct current is: Perform speed regulation and angle integration on the final DC current to obtain the rotor angle of the three-phase brushless motor.

9. A motor rotor angle calculation device, characterized in that, It includes a processor and a memory; The memory is used to store a computer program and transmit the computer program to the processor; The processor is used to execute the motor rotor angle calculation method according to any one of claims 1-5 based on the instructions in the computer program.

10. A storage medium storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to execute the motor rotor angle calculation method according to any one of claims 1-5.

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