Methods, systems, electronic devices, and readable storage media for estimating the electrical angle of an electric motor

Abstract

This invention provides a method, system, electronic device, and readable storage medium for estimating the electrical angle of a motor. The method includes: acquiring three-phase current information and three-phase voltage information at the current moment; acquiring back electromotive force (EMF) estimation information or high-frequency response current estimation information at the current moment based on the three-phase current information and three-phase voltage information; acquiring back EMF error information based on the back EMF estimation information at the current moment and the electrical angle estimation information at the previous moment; or acquiring high-frequency response current error information based on the high-frequency response current estimation information at the current moment and the electrical angle estimation information at the previous moment; acquiring electrical angular velocity estimation information based on the back EMF error information or the high-frequency response current error information; and acquiring electrical angle estimation information based on the electrical angular velocity estimation information. This invention can solve the problem of steady-state error in the motor electrical angle estimated using a second-order phase-locked loop algorithm when the motor angular velocity changes.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method, system, electronic device, and readable storage medium for estimating the electrical angle of a motor. Background Technology

[0002] Brushless DC motors (BLDC) possess advantages such as high efficiency, good speed regulation performance, high power density, simple structure, low noise, and long lifespan, and are widely used in the automotive industry, aerospace, and home appliances. Sensorless technology can effectively reduce system costs and improve system reliability. Therefore, researching sensorless BLDC motor control algorithms with high control precision and strong anti-interference capabilities is of great significance.

[0003] Currently, the main sensorless control algorithms for BLDC motors include sliding mode observer algorithms based on extended back EMF models (referred to as the back EMF method, such as...). Figure 1 (as shown) and a position error signal decoupling algorithm based on high-frequency injection current (referred to as the high-frequency injection method, such as...) Figure 2 (As shown). The former is suitable for the high-speed range, while the latter is suitable for the low-speed / zero-speed range. The back EMF method works by using a sliding mode observer to estimate the magnitude of the back EMF generated during rotor rotation, then using a second-order phase-locked loop algorithm to estimate the electrical angle value of the motor based on the estimated back EMF, and finally substituting the estimated electrical angle value into the entire closed-loop control logic. The high-frequency injection method involves injecting a high-frequency current (with a frequency similar to the PWM wave frequency) into the d-axis of the BLDC motor, and combining this with the motor's salient polarity to obtain a high-frequency response current signal, finally using a second-order phase-locked loop algorithm to estimate the motor's electrical angle value.

[0004] Currently, a second-order phase-locked loop (PLL) algorithm is commonly used to estimate the electrical angle of a BLDC motor based on the back electromotive force / high-frequency response current signal. This algorithm is suitable for operating conditions where the motor angular velocity is constant. However, when the motor angular velocity changes (i.e., the angular acceleration is not zero), the electrical angle estimated by the second-order PLL algorithm will have a steady-state error. The steady-state error of the electrical angle may adversely affect the control performance of the motor.

[0005] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method for estimating the electrical angle of a motor, an electronic device, and a readable storage medium, which can solve the problem of steady-state error in the electrical angle of the motor estimated by the second-order phase-locked loop algorithm when the motor angular velocity changes, thereby improving the closed-loop control effect of the motor.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for estimating the electrical angle of a motor, comprising:

[0008] Obtain the three-phase current and three-phase voltage information of the motor at the current moment;

[0009] Based on the three-phase current information and three-phase voltage information of the motor at the current moment, obtain the back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment;

[0010] Based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the back EMF error information of the motor at the current moment is obtained; or based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the high-frequency response current error information of the motor at the current moment is obtained.

[0011] Based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment, a preset third-order phase-locked loop algorithm is used to obtain the estimated electric angular velocity information of the motor at the current moment.

[0012] Based on the estimated electrical angular velocity of the motor at the current moment, the estimated electrical angle of the motor at the current moment is obtained.

[0013] Optionally, obtaining the back electromotive force estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes:

[0014] Based on the three-phase current and three-phase voltage information of the motor at the current moment, the sliding mode observer algorithm is used to obtain the estimated value of the back electromotive force of the motor in the α and β axis coordinate system at the current moment.

[0015] Optionally, obtaining the high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes:

[0016] Based on the three-phase current and three-phase voltage information of the motor at the current moment, a position error signal decoupling algorithm is used to obtain the high-frequency response current envelope value of the motor in the α and β axis coordinate system at the current moment.

[0017] Optionally, obtaining the back EMF error information of the motor at the current moment based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes:

[0018] Based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial back EMF error information of the motor at the current moment is obtained.

[0019] The initial back EMF error information of the motor at the current moment is normalized to obtain the back EMF error information of the motor at the current moment.

[0020] Optionally, obtaining the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes:

[0021] Based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial high-frequency response current error information of the motor at the current moment is obtained.

[0022] The initial high-frequency response current error information of the motor at the current moment is normalized to obtain the high-frequency response current error information of the motor at the current moment.

[0023] Optionally, the step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the back electromotive force error information of the motor at the current moment includes:

[0024] Based on the back EMF error information of the motor at the current moment, the electric angular velocity estimation information of the motor at the current moment is obtained by using a first preset proportional coefficient, a first preset first integral coefficient, and a first preset second integral coefficient. The first preset proportional coefficient, the first preset first integral coefficient, and the first preset second integral coefficient are all greater than 0, and the product of the first preset proportional coefficient and the first preset first integral coefficient is greater than the first preset second integral coefficient.

[0025] Optionally, the step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the high-frequency response current error information of the motor at the current moment includes:

[0026] Based on the high-frequency response current error information of the motor at the current moment, the electric angular velocity estimation information of the motor at the current moment is obtained by using the second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient. The second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient are all greater than 0, and the product of the second preset proportional coefficient and the second preset first integral coefficient is greater than the second preset second integral coefficient.

[0027] To address the aforementioned technical problems, the present invention also provides a motor electrical angle estimation system, comprising:

[0028] The first acquisition module is configured to acquire the three-phase current information and three-phase voltage information of the motor at the current moment;

[0029] The second acquisition module is configured to acquire back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment.

[0030] The error information acquisition module is configured to acquire the back electromotive force error information of the motor at the current moment based on the back electromotive force estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment; or to acquire the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment.

[0031] The electric angular velocity estimation module is configured to obtain the electric angular velocity estimation information of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment.

[0032] The electrical angle estimation module is configured to obtain the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment.

[0033] To address the aforementioned technical problems, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the motor electrical angle estimation method described above.

[0034] To address the aforementioned technical problems, the present invention also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the motor electrical angle estimation method described above.

[0035] Compared with the prior art, the electric angle estimation method, system, electronic device, and readable storage medium provided by the present invention have the following advantages:

[0036] The electric angle estimation method for a motor provided by this invention first obtains the three-phase current information and three-phase voltage information of the motor at the current moment; then, based on the three-phase current information and three-phase voltage information of the motor at the current moment, it obtains the back electromotive force (EMF) estimation information or high-frequency response current estimation information of the motor at the current moment; then, based on the back EMF estimation information of the motor at the current moment and the electric angle estimation information of the motor at the previous moment, it obtains the back EMF error information of the motor at the current moment; or, based on the high-frequency response current estimation information of the motor at the current moment and the electric angle estimation information of the motor at the previous moment, it obtains the high-frequency response current error information of the motor at the current moment; then, based on the back EMF error information or high-frequency response current error information of the motor at the current moment, it uses a preset third-order phase-locked loop (PLL) algorithm to obtain the electric angular velocity estimation information of the motor at the current moment; finally, based on the electric angular velocity estimation information of the motor at the current moment, it obtains the electric angle estimation information of the motor at the current moment. Therefore, the motor electrical angle estimation method provided by the present invention obtains the electrical angular velocity estimation information of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment, and obtains the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment. This can ensure that there is no steady-state error in the estimation of electrical angle when the angular velocity of the motor changes, thereby improving the closed-loop control effect of the motor.

[0037] Since the electric motor angle estimation system, electronic device, and readable storage medium provided by this invention belong to the same inventive concept as the electric motor angle estimation method provided by this invention, the electric motor angle estimation system, electronic device, and readable storage medium provided by this invention have at least all the beneficial effects of the electric motor angle estimation method provided by this invention. For details, please refer to the relevant descriptions of the beneficial effects of the electric motor angle estimation method provided by this invention above. Therefore, the beneficial effects of the electric motor angle estimation system, electronic device, and readable storage medium provided by this invention will not be elaborated here. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a sliding mode observer algorithm based on an extended back EMF model in the prior art.

[0039] Figure 2 This is a schematic diagram of a position error signal decoupling algorithm based on high-frequency injection current in the prior art.

[0040] Figure 3 A flowchart illustrating a method for estimating the electrical angle of a motor according to an embodiment of the present invention;

[0041] Figure 4A schematic flowchart of an electric angle estimation method based on the back electromotive force method provided in one embodiment of the present invention;

[0042] Figure 5 A schematic flowchart of an electrical angle estimation method based on high-frequency injection provided in one embodiment of the present invention;

[0043] Figure 6 A block diagram of a motor electrical angle estimation system provided in one embodiment of the present invention;

[0044] Figure 7 This is a block diagram of an electronic device provided according to an embodiment of the present invention.

[0045] First acquisition module - 110; Second acquisition module - 120; Error information acquisition module - 130; Electrical angular velocity estimation module - 140; Electrical angle estimation module - 150;

[0046] Processor-210; Communication interface-220; Memory-230; Communication bus-240. Detailed Implementation

[0047] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the motor electrical angle estimation method, system, electronic device, and readable storage medium proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clarify the purpose provided by this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes and to enable those skilled in the art to understand and read them, and are not intended to limit the implementation conditions of this invention. Any modifications to the structure, changes in proportions, or adjustments to the size, provided they produce the same or similar effects and achieve the same objectives as this invention, should still fall within the scope of the technical content disclosed in this invention.

[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The singular forms “a,” “an,” and “the” include plural objects. The term “or” is generally used to mean “and / or,” the term “several” is generally used to mean “at least one,” and the term “at least two” is generally used to mean “two or more.” Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0049] Furthermore, in the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] To facilitate understanding, before introducing the motor electrical angle estimation method, system, electronic device, and readable storage medium provided by this invention, a brief introduction to the research background of this invention will be given first.

[0051] In existing technologies, when using a second-order phase-locked loop (PLL) algorithm to estimate the electrical angle of a motor, a steady-state error exists in the estimation of the electrical angle under conditions where the motor's electrical angular velocity changes. A commonly used second-order PLL algorithm is:

[0052]

[0053] in, This is an estimated value for the electric angular velocity, k. p ki ε is the controller coefficient. n This refers to the normalized back electromotive force error or high-frequency response current error. When the motor angular acceleration is not zero (i.e.... From this, the steady-state error of the electrical angle estimate of the second-order phase-locked loop can be derived as follows: The greater the angular acceleration, the greater the steady-state error of the electrical angle estimate. i The larger the parameter, the smaller the steady-state error of the electrical angle estimate, but k i Increasing the parameters can affect the stability of the control algorithm.

[0054] The core idea of ​​this invention is to provide a method, system, electronic device, and readable storage medium for estimating the electrical angle of a motor, which can solve the problem of steady-state error in the electrical angle of the motor estimated by the second-order phase-locked loop algorithm when the motor angular velocity changes, thereby improving the closed-loop control effect of the motor.

[0055] It should be noted that the motor electrical angle estimation method provided by this invention can be applied to the motor electrical angle estimation system provided by this invention. The motor electrical angle estimation system provided by this invention can be configured on the electronic device provided by this invention, which can be configured in an electric vehicle. The electronic device can be a hardware device with various operating systems and can be used as a motor controller. Furthermore, it should be noted that, as those skilled in the art will understand, the motor electrical angle estimation method provided by this invention is not only applicable to BLDC motors but also to other types of motors, such as permanent magnet synchronous motors. Additionally, it should be noted that, as those skilled in the art will understand, the motor electrical angle estimation method provided by this invention is not only applicable to motors without position sensors but also to motors with position sensors that are turned off or malfunctioning.

[0056] To achieve the above-mentioned goals, this invention provides a method for estimating the electrical angle of a motor. Please refer to [the relevant documentation]. Figure 3 This is a flowchart of a motor electrical angle estimation method provided in one embodiment of the present invention, as shown below. Figure 3 As shown, the method for estimating the electrical angle of a motor provided by this invention includes the following steps:

[0057] Step S100: Obtain the three-phase current information and three-phase voltage information of the motor at the current moment.

[0058] Step S200: Based on the three-phase current information and three-phase voltage information of the motor at the current moment, obtain the back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment.

[0059] Step S300: Obtain the back EMF error information of the motor at the current moment based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment; or obtain the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment.

[0060] Step S400: Based on the back EMF error information or high-frequency response current error information of the motor at the current moment, a preset third-order phase-locked loop algorithm is used to obtain the estimated electric angular velocity information of the motor at the current moment.

[0061] Step S500: Obtain the electric angle estimation information of the motor at the current moment based on the electric angular velocity estimation information of the motor at the current moment.

[0062] Therefore, the motor electrical angle estimation method provided by the present invention obtains the electrical angular velocity estimation information of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment, and obtains the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment. This can ensure that there is no steady-state error in the estimation of electrical angle when the angular velocity of the motor changes, thereby improving the closed-loop control effect of the motor.

[0063] Please continue to refer to this. Figure 4 This is a schematic diagram of the electrical angle estimation method based on the back electromotive force method provided in one embodiment of the present invention. Figure 4 As shown, in some exemplary embodiments, obtaining the back electromotive force estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes:

[0064] Based on the three-phase current and three-phase voltage information of the motor at the current moment, the sliding mode observer algorithm is used to obtain the estimated value of the back electromotive force of the motor in the α and β axis coordinate system at the current moment.

[0065] Because the sliding mode observer estimates motor state variables using a closed-loop system, it exhibits strong robustness and stability. Furthermore, it converges quickly, is insensitive to motor parameters, and requires minimal computation while maintaining high accuracy. Therefore, by using the three-phase current signal I of the motor at the current moment… a I b I c and three-phase voltage signal U a U b U cBy employing a sliding mode observer, the estimated back electromotive force of the motor in the α and β axis coordinate system at the current moment can be obtained quickly and accurately.

[0066] It should be noted that the sliding mode observer algorithm is used to obtain the estimated back electromotive force of the motor in the α and β axis coordinate systems. For details, please refer to Figure 1 The sliding mode observer algorithm based on the extended back EMF model shown is related to... Figure 1 Further details regarding the sliding mode observer algorithm based on the extended back EMF model can be found in relevant techniques well-known to those skilled in the art, and will not be elaborated upon here. It should also be noted that, as those skilled in the art will understand, Figure 1 I in q,ref I represents the q-axis reference current. d,ref U represents the d-axis reference current. d U q U represents the voltage signal of the motor in the d-q axis coordinate system. α U β I represents the voltage signal of the motor in the α and β axis coordinate system. d I q I represents the current signal of the motor in the d-q axis coordinate system. α I β This represents the current signal of the motor in the α and β axis coordinate system, and SVPWM represents space vector pulse width modulation.

[0067] Please continue to refer to this. Figure 4 ,like Figure 4 As shown, in some exemplary embodiments, obtaining the back EMF error information of the motor at the current moment based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes:

[0068] Based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial back EMF error information of the motor at the current moment is obtained.

[0069] The initial back EMF error information of the motor at the current moment is normalized to obtain the back EMF error information of the motor at the current moment.

[0070] Therefore, by first estimating the back EMF of the motor at the current moment and estimating the electrical angle of the motor at the previous moment, the initial back EMF error information of the motor at the current moment is obtained. Then, the initial back EMF error information of the motor at the current moment is normalized to obtain the back EMF error information of the motor at the current moment. This can convert the back EMF error information into dimensionless information, which makes it easier to subsequently obtain the electrical angular velocity estimation information of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the back EMF error information of the motor at the current moment.

[0071] Specifically, the initial back electromotive force error ε can be calculated using the following formula. e :

[0072]

[0073] In the formula, This is the estimated electrical angle value of the motor at the previous moment.

[0074] Using the calculated initial back electromotive force error ε e The normalized back electromotive force error ε can be calculated using the following normalization formula. e,n :

[0075]

[0076] In some exemplary embodiments, the step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the back electromotive force error information of the motor at the current moment includes:

[0077] Based on the back electromotive force error information of the motor at the current moment, the electric angular velocity estimation information of the motor at the current moment is obtained by using a first preset proportional coefficient, a first preset first integral coefficient, and a first preset second integral coefficient. The first preset proportional coefficient, the first preset first integral coefficient, and the first preset second integral coefficient are all greater than 0, and the product of the first preset first integral coefficient and the first preset second integral coefficient is greater than the first preset proportional coefficient.

[0078] Specifically, the estimated electrical angular velocity of the motor at the current moment can be calculated using the following first-order third-order phase-locked loop formula.

[0079]

[0080] Where, k e,2 k is the first preset proportionality coefficient. e,1 Let k be the first preset integral coefficient. e,0t represents the first preset quadratic integral coefficient, and t represents the duration between the current time and the initial time.

[0081] It should be noted that, as those skilled in the art will understand, the initial time refers to the initialization time of the motor electrical angle estimation method provided by this invention. When the motor starts, the motor electrical angle estimation method provided by this invention is initialized, and t in the above first third-order phase-locked loop formula is the continuous running time of the motor. It should also be noted that, as those skilled in the art will understand, the estimated electrical angle value of the motor at the initial time can be set to 0.

[0082] Because the estimated value of the back electromotive force of the motor in the α and β axis coordinate system With respect to the actual electric angular velocity ω of the motor e and the actual electrical angle θ e The following relation exists:

[0083]

[0084] Where, ψ f The excitation flux of the permanent magnet in the motor.

[0085] Therefore, the initial back electromotive force error ε mentioned above can be... e The calculation formula can be rewritten as follows:

[0086]

[0087] Furthermore, the aforementioned back electromotive force error ε can be further... e,n The calculation formula can be rewritten as follows:

[0088]

[0089] When the actual value of the electrical angle θ e Compared with the estimated value When the difference is small It can be considered Therefore, it can be considered that

[0090] Therefore, based on the above first and third order phase-locked loop formulas, the dynamic equation for the electrical angle estimation error can be derived as follows:

[0091]

[0092] in, To estimate the error in electrical angle, θ e For the actual electrical angle, They are respectively The first, second, and third derivatives.

[0093] The condition for the stability of the zero solution of the above dynamic equation is:

[0094]

[0095] Therefore, by using the first preset proportional coefficient k e,2 The first preset first integral coefficient k e,1 and the first preset quadratic integral coefficient k e,0 All are set to be greater than 0, and the first preset proportional coefficient k e,2 With the first preset first integral coefficient k e,1 The product is greater than the first preset quadratic integral coefficient k e,0 This allows the third-order phase-locked loop algorithm to converge, thereby effectively ensuring that the steady-state error of the electrical angle estimated using the preset third-order phase-locked loop algorithm is 0. It should be noted that, as those skilled in the art will understand, the present invention addresses the first preset proportionality coefficient k. e,2 The first preset integral coefficient k e,1 and the first preset quadratic integral coefficient k e,0 The specific value is not limited.

[0096] Please continue to refer to this. Figure 4 ,like Figure 4 As shown, in some exemplary embodiments, obtaining the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment includes:

[0097] The estimated electrical angle of the motor at the current moment is calculated using the following formula.

[0098]

[0099] Please continue to refer to this. Figure 5 This is a schematic diagram of the electrical angle estimation method based on high-frequency injection provided by an embodiment of the present invention. Figure 5 As shown, in some exemplary embodiments, obtaining the high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes:

[0100] Based on the three-phase current and three-phase voltage information of the motor at the current moment, a position error signal decoupling algorithm is used to obtain the high-frequency response current envelope value of the motor in the α and β axis coordinate system at the current moment.

[0101] Therefore, by using the three-phase current signal I of the motor at the current moment... a I b I c and three-phase voltage signal U a U b Uc By employing a position error signal decoupling algorithm, the high-frequency response current envelope value I of the motor at the current moment in the α and β axis coordinate system can be obtained quickly and stably. αh I βh .

[0102] It should be noted that the position error signal decoupling algorithm is used to obtain the high-frequency response current envelope value I of the motor in the α and β axis coordinate system. αh I βh For details, please refer to Figure 2 The position error signal decoupling algorithm based on high-frequency injection current shown is about Figure 2 The specific details of the position error signal decoupling algorithm based on high-frequency injection current shown can be found in relevant technologies known to those skilled in the art, and will not be elaborated upon here. It should also be noted that, as those skilled in the art will understand, Figure 2 I in q,ref I represents the q-axis reference current. d,ref U represents the d-axis reference current. d U q U represents the voltage signal of the motor in the d-q axis coordinate system. α U β I represents the voltage signal of the motor in the α and β axis coordinate system. d I q I represents the current signal of the motor in the d-q axis coordinate system. α I β U represents the current signal of the motor in the α and β axis coordinate system. inj This represents the amplitude of the high-frequency injected signal.

[0103] Please continue to refer to this. Figure 5 ,like Figure 5 As shown, in some exemplary embodiments, obtaining the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes:

[0104] Based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial high-frequency response current error information of the motor at the current moment is obtained.

[0105] The initial high-frequency response current error information of the motor at the current moment is normalized to obtain the high-frequency response current error information of the motor at the current moment.

[0106] Therefore, by first estimating the high-frequency response current of the motor at the current moment and estimating the electrical angle of the motor at the previous moment, the initial high-frequency response current error information of the motor at the current moment is obtained; then, the initial high-frequency response current error information of the motor at the current moment is normalized to obtain the high-frequency response current error information of the motor at the current moment. This can convert the high-frequency response current error information into dimensionless information, which makes it easier to subsequently obtain the electrical angular velocity estimation information of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the high-frequency response current error information of the motor at the current moment.

[0107] Specifically, the initial high-frequency response current error ε can be calculated using the following formula. i :

[0108]

[0109] Using the calculated initial high-frequency response current error ε i The normalized high-frequency response current error ε can be calculated using the following normalization formula. i,n :

[0110]

[0111] In some exemplary embodiments, the step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the high-frequency response current error information of the motor at the current moment includes:

[0112] Based on the high-frequency response current error information of the motor at the current moment, the electric angular velocity estimation information of the motor at the current moment is obtained by using the second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient. The second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient are all greater than 0, and the product of the second preset proportional coefficient and the second preset first integral coefficient is greater than the second preset second integral coefficient.

[0113] Specifically, the estimated electrical angular velocity of the motor at the current moment can be calculated using the following second- or third-order phase-locked loop formula.

[0114]

[0115] Where, k i,2 k is the second preset proportional coefficient. i,1 For the second preset first-order integral coefficient, k i,0 t represents the second preset quadratic integral coefficient, and t represents the duration between the current time and the initial time.

[0116] Because the high-frequency response current envelope value of the motor in the α and β axis coordinate system is different from the actual electrical angle θ of the motor. e The following relationship exists:

[0117]

[0118] Among them, L avg Let L be the average of the d-axis and q-axis inductance of the motor. diff ω is half the difference between the d-axis inductance and the q-axis inductance of the motor. h L is the frequency of the high-frequency injected signal. d L is the d-axis inductance of the motor. q Let I be the q-axis inductance of the motor, and k be the value of the high-frequency response current envelope of the motor in the α and β axis coordinate systems at the current moment. αh and I βh The sign of k is such that if k was 1 at the previous time, then k is -1 at the current time.

[0119] Therefore, the initial high-frequency response current error ε mentioned above can be used to... i The calculation formula can be rewritten as follows:

[0120]

[0121] Furthermore, the aforementioned back electromotive force error ε can be further... e,n The calculation formula can be rewritten as follows:

[0122]

[0123] When the actual value of the electrical angle θ e Compared with the estimated value When the difference is small It can be considered Therefore, it can be considered that

[0124] Therefore, based on the above formulas for the second and third order phase-locked loops, the dynamic equation for the electrical angle estimation error can be derived as follows:

[0125]

[0126] in, To estimate the error in electrical angle, θ e For the actual electrical angle, They are respectively The first, second, and third derivatives.

[0127] The condition for the stability of the zero solution of the above dynamic equation is:

[0128]

[0129] Therefore, by using the second preset proportional coefficient k i,2 The second preset first integral coefficient k i,1 and the second preset quadratic integral coefficient k i,0 All are set to be greater than 0, and the second preset proportional coefficient k i,2 With the second preset first integral coefficient k i,1 The product is greater than the second preset quadratic integral coefficient k i,0 This allows the third-order phase-locked loop algorithm to converge, thereby effectively ensuring that the steady-state error of the electrical angle estimated using the preset third-order phase-locked loop algorithm is 0. It should be noted that, as those skilled in the art will understand, the present invention addresses the second preset proportionality coefficient k. i,2 The second preset first integral coefficient k i,1 and the second preset quadratic integral coefficient k i,0 The specific value is not limited.

[0130] Based on the same inventive concept, this invention also provides a motor electrical angle estimation system, please refer to... Figure 6 This is a block diagram of a motor electrical angle estimation system provided in one embodiment of the present invention. Figure 6 As shown, the electric angle estimation system for motors provided by the present invention includes a first acquisition module 110, a second acquisition module 120, an error information acquisition module 130, an electric angular velocity estimation module 140, and an electric angle estimation module 150. The first acquisition module 110 is configured to acquire the three-phase current information and three-phase voltage information of the motor at the current moment; the second acquisition module 120 is configured to acquire the back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment; the error information acquisition module 130 is configured to acquire the back electromotive force error information of the motor at the current moment based on the back electromotive force estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment; or acquire the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment; the electrical angular velocity estimation module 140 is configured to acquire the electrical angular velocity estimation information of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment; the electrical angle estimation module 150 is configured to acquire the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment.

[0131] Therefore, the motor electrical angle estimation system provided by the present invention obtains the electrical angular velocity estimation information of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment, and obtains the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment. This can ensure that there is no steady-state error in the estimation of electrical angle when the angular velocity of the motor changes, thereby improving the closed-loop control effect of the motor.

[0132] In some exemplary embodiments, the second acquisition module 120 is configured to acquire the estimated back electromotive force of the motor in the α and β axis coordinate system at the current moment by using a sliding mode observer algorithm based on the three-phase current information and three-phase voltage information of the motor at the current moment; or to acquire the high-frequency response current envelope value of the motor in the α and β axis coordinate system at the current moment by using a position error signal decoupling algorithm based on the three-phase current information and three-phase voltage information of the motor at the current moment.

[0133] In some exemplary embodiments, the error information acquisition module 130 is configured to acquire the initial back EMF error information of the motor at the current moment based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, and to normalize the initial back EMF error information of the motor at the current moment to obtain the back EMF error information of the motor at the current moment.

[0134] In some exemplary embodiments, the error information acquisition module 130 is configured to acquire the electric angular velocity estimation information of the motor at the current moment based on the back electromotive force error information of the motor at the current moment, using a first preset proportional coefficient, a first preset first integral coefficient, and a first preset second integral coefficient, wherein the first preset proportional coefficient, the first preset first integral coefficient, and the first preset second integral coefficient are all greater than 0, and the product of the first preset proportional coefficient and the first preset first integral coefficient is greater than the first preset second integral coefficient.

[0135] In some exemplary embodiments, the error information acquisition module 130 is configured to acquire the initial high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, and to normalize the initial high-frequency response current error information of the motor at the current moment to obtain the high-frequency response current error information of the motor at the current moment.

[0136] In some exemplary embodiments, the error information acquisition module 130 is configured to acquire the electric angular velocity estimation information of the motor at the current moment based on the high-frequency response current error information of the motor at the current moment, using a second preset proportional coefficient, a second preset first integral coefficient, and a second preset second integral coefficient, wherein the second preset proportional coefficient, the second preset first integral coefficient, and the second preset second integral coefficient are all greater than 0, and the product of the second preset proportional coefficient and the second preset first integral coefficient is greater than the second preset second integral coefficient.

[0137] Based on the same inventive concept, the present invention also provides an electronic device, please refer to [reference needed]. Figure 7 This is a block diagram of an electronic device provided in one embodiment of the present invention. Figure 7 As shown, the electronic device provided by this invention includes a processor 210 and a memory 230. The memory 230 stores a computer program, which, when executed by the processor 210, implements the motor electrical angle estimation method described above. Since the electronic device and the motor electrical angle estimation method provided by this invention belong to the same inventive concept, the electronic device provided by this invention possesses at least all the beneficial effects of the motor electrical angle estimation method provided by this invention. For details, please refer to the relevant descriptions of the beneficial effects of the motor electrical angle estimation method provided by this invention above; therefore, the beneficial effects of the electronic device provided by this invention will not be repeated here.

[0138] like Figure 7 As shown, the electronic device provided by this invention also includes a communication interface 220 and a communication bus 240, wherein the processor 210, the communication interface 220, and the memory 230 communicate with each other through the communication bus 240. The communication bus 240 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus 240 can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used to represent it in the figure, but this does not indicate that there is only one bus or one type of bus. The communication interface 220 is used for communication between the above-mentioned electronic device and other devices.

[0139] The processor 210 referred to in this invention can be a Central Processing Unit (CPU), or 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 can be a microprocessor or any conventional processor. The processor 210 is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines.

[0140] The memory 230 can be used to store the computer program. The processor 210 implements various functions of the electronic device by running or executing the computer program stored in the memory 230 and calling data stored in the memory 230. The memory 230 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable memory (PROM), electrically programmable memory (EPROM), electrically erasable programmable memory (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, random access memory is available in a variety of forms, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous random access memory (SDRAM), dual data rate synchronous random access memory (DDRSDRAM), enhanced synchronous random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), memory bus direct random access memory (RDRAM), direct memory bus dynamic random access memory (DRDRAM), and memory bus dynamic random access memory (RDRAM), etc.

[0141] This invention also provides a readable storage medium storing a computer program that, when executed by a processor, can implement the motor electrical angle estimation method described above. Since the readable storage medium and the motor electrical angle estimation method provided by this invention belong to the same inventive concept, the readable storage medium provided by this invention possesses at least all the beneficial effects of the motor electrical angle estimation method provided by this invention. For details, please refer to the relevant descriptions of the beneficial effects of the motor electrical angle estimation method provided by this invention above; therefore, the beneficial effects of the readable storage medium provided by this invention will not be elaborated upon here.

[0142] The readable storage medium provided by this invention can be any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples (not exhaustive) of computer-readable storage media include: electrical connections having one or more wires, portable computer hard disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, apparatus, or device.

[0143] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber, RF, etc., or any suitable combination thereof.

[0144] In summary, compared with the prior art, the motor electrical angle estimation method, system, electronic device, and readable storage medium provided by the present invention have the following beneficial effects:

[0145] This invention obtains the estimated electrical angular velocity of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment. Based on the estimated electrical angular velocity information of the motor at the current moment, the estimated electrical angle information of the motor at the current moment is obtained. This can ensure that there is no steady-state error in the estimation of electrical angle when the angular velocity of the motor changes, thereby improving the closed-loop control effect of the motor.

[0146] It should be noted that computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. These programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0147] It should be noted that the apparatus and methods disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments herein. In this regard, each block in a flowchart or block diagram may represent a module, program, or part of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system to perform the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of this article can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0148] It should also be noted that the above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure are within the protection scope of the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for estimating the electrical angle of a motor, characterized in that, include: Obtain the three-phase current and three-phase voltage information of the motor at the current moment; Based on the three-phase current information and three-phase voltage information of the motor at the current moment, obtain the back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment; Based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the back EMF error information of the motor at the current moment is obtained. Alternatively, based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the high-frequency response current error information of the motor at the current moment can be obtained. Based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment, a preset third-order phase-locked loop algorithm is used to obtain the estimated electric angular velocity information of the motor at the current moment. Based on the estimated electrical angular velocity of the motor at the current moment, the estimated electrical angle of the motor at the current moment is obtained; The step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the back electromotive force error information of the motor at the current moment includes: Based on the back electromotive force error information of the motor at the current moment, the estimated electrical angular velocity information of the motor at the current moment is obtained using a first preset proportional coefficient, a first preset first integral coefficient, and a first preset second integral coefficient. Wherein, the first preset proportional coefficient, the first preset first integral coefficient, and the first preset second integral coefficient are all greater than 0, and the product of the first preset proportional coefficient and the first preset first integral coefficient is greater than the first preset second integral coefficient; or The step of obtaining the estimated electrical angular velocity of the motor at the current moment using a preset third-order phase-locked loop algorithm based on the high-frequency response current error information of the motor at the current moment includes: Based on the high-frequency response current error information of the motor at the current moment, the electric angular velocity estimation information of the motor at the current moment is obtained by using the second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient. The second preset proportional coefficient, the second preset first integral coefficient and the second preset second integral coefficient are all greater than 0, and the product of the second preset proportional coefficient and the second preset first integral coefficient is greater than the second preset second integral coefficient.

2. The method for estimating the electrical angle of a motor according to claim 1, characterized in that, The step of obtaining the back electromotive force estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes: Based on the three-phase current and three-phase voltage information of the motor at the current moment, a sliding mode observer algorithm is used to obtain the motor's current voltage at the current moment. α , β Estimated back electromotive force in axial coordinate system.

3. The method for estimating the electrical angle of a motor according to claim 1, characterized in that, The step of obtaining the high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment includes: Based on the three-phase current and three-phase voltage information of the motor at the current moment, a position error signal decoupling algorithm is used to obtain the position error signal of the motor at the current moment. α , β The high-frequency response current envelope value in the axial coordinate system.

4. The method for estimating the electrical angle of a motor according to claim 1, characterized in that, The step of obtaining the back EMF error information of the motor at the current moment based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes: Based on the back EMF estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial back EMF error information of the motor at the current moment is obtained. The initial back EMF error information of the motor at the current moment is normalized to obtain the back EMF error information of the motor at the current moment.

5. The method for estimating the electrical angle of a motor according to claim 1, characterized in that, The step of obtaining the high-frequency response current error information of the motor at the current moment based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment includes: Based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the initial high-frequency response current error information of the motor at the current moment is obtained. The initial high-frequency response current error information of the motor at the current moment is normalized to obtain the high-frequency response current error information of the motor at the current moment.

6. A motor electrical angle estimation system, characterized in that, include: The first acquisition module is configured to acquire the three-phase current information and three-phase voltage information of the motor at the current moment; The second acquisition module is configured to acquire back electromotive force estimation information or high-frequency response current estimation information of the motor at the current moment based on the three-phase current information and three-phase voltage information of the motor at the current moment. The error information acquisition module is configured to acquire the back electromotive force error information of the motor at the current moment based on the back electromotive force estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment. Alternatively, based on the high-frequency response current estimation information of the motor at the current moment and the electrical angle estimation information of the motor at the previous moment, the high-frequency response current error information of the motor at the current moment can be obtained. The electric angular velocity estimation module is configured to obtain the electric angular velocity estimation information of the motor at the current moment by using a preset third-order phase-locked loop algorithm based on the back electromotive force error information or high-frequency response current error information of the motor at the current moment. The electrical angle estimation module is configured to obtain the electrical angle estimation information of the motor at the current moment based on the electrical angular velocity estimation information of the motor at the current moment; The electric angular velocity estimation module is configured to obtain the electric angular velocity estimation information of the motor at the current moment based on the back electromotive force error information of the motor at the current moment, using a first preset proportional coefficient, a first preset first integral coefficient, and a first preset second integral coefficient, wherein the first preset proportional coefficient, the first preset first integral coefficient, and the first preset second integral coefficient are all greater than 0, and the product of the first preset proportional coefficient and the first preset first integral coefficient is greater than the first preset second integral coefficient; or, based on the high-frequency response current error information of the motor at the current moment, it uses a second preset proportional coefficient, a second preset first integral coefficient, and a second preset second integral coefficient to obtain the electric angular velocity estimation information of the motor at the current moment, wherein the second preset proportional coefficient, the second preset first integral coefficient, and the second preset second integral coefficient are all greater than 0, and the product of the second preset proportional coefficient and the second preset first integral coefficient is greater than the second preset second integral coefficient.

7. An electronic device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the motor electrical angle estimation method according to any one of claims 1 to 5.

8. A readable storage medium, characterized in that, The readable storage medium stores a computer program, which, when executed by a processor, implements the motor electrical angle estimation method according to any one of claims 1 to 5.

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