Angle error compensation device for linear Hall encoder of permanent magnet synchronous motor

Abstract

The present invention relates to a permanent magnet synchronous motor linear Hall encoder angle error compensation device, comprising: a first low-pass filter module, a first maximum and minimum value acquisition module, a second low-pass filter module, a second maximum and minimum value acquisition module, an amplitude compensation module, a bias compensation module, a phase compensation module, a PI module, an Arctan / Arccot ​​module and a phase-locked loop module; the amplitude compensation module, the bias compensation module and the phase compensation module are all based on the SIN signal and the COS signal of the linear Hall sensor for compensation. Compared with the prior art, the present invention can reduce the error of the signal output by the linear Hall and obtain a more accurate permanent magnet synchronous motor rotor angle value.

Description

Technical Field

[0001] The invention relates to the field of permanent magnet synchronous motor position signal processing, and in particular to a permanent magnet synchronous motor linear Hall encoder angle error compensation device. Background Art

[0002] Permanent magnet synchronous motor (PMSM) has been widely used in the field of new energy vehicles in recent years. Its advantages such as high efficiency, high power density and low torque pulsation have been favored by customers. From the perspective of engineering application and cost, the use of linear Hall encoders is still the mainstream choice in the market, which not only ensures the accuracy of the angle, but also has a relatively acceptable price. However, due to reasons such as component accuracy, installation tolerance, magnetic field strength, rotor eccentricity, electromagnetic interference, etc., the SINCOS analog quantity output by the linear Hall will be abnormally disturbed, thereby affecting the smooth output of the permanent magnet synchronous motor torque. Therefore, how to process the signal output by the linear Hall and parse the corresponding angle has become a current research hotspot. Summary of the invention

[0003] The purpose of the present invention is to provide a permanent magnet synchronous motor linear Hall encoder angle error compensation device in order to overcome the defects of the above-mentioned prior art that the linear Hall output signal has errors such as amplitude, DC bias, orthogonality, etc.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A permanent magnet synchronous motor linear Hall encoder angle error compensation device, comprising:

[0006] The first low-pass filter module is used to perform a first-order low-pass filter on the SIN signal of the linear Hall sensor, and output a SIN signal with phase delay and high-frequency components filtered out;

[0007] A first maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the SIN signal generated by the first low-pass filter module;

[0008] A second low-pass filter module, used for performing a first-order low-pass filter on the COS signal of the linear Hall sensor, and outputting a COS signal with a phase delay and high-frequency components filtered out, wherein the second low-pass filter module has a parameter port for adjusting the filtering performance;

[0009] The second maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the COS signal generated by the second low-pass filter module;

[0010] An amplitude compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform amplitude compensation on the filtered value of the second low-pass filter module to obtain an Acos value;

[0011] The bias compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform bias compensation on the Acos value to obtain the Ocos value;

[0012] A phase compensation module is used to compare the orthogonal characteristics of the filter processing value of the first low-pass filter module and the Ocos value to form an orthogonal error value, perform phase compensation on the filter processing value of the first low-pass filter module to obtain a Psin value, and perform phase compensation on the Ocos value to obtain a Pcos value;

[0013] A PI module, used for performing PI adjustment on the filtering performance of the second low-pass filter module according to the orthogonal error value, so that the phase of the filtering processing value of the first low-pass filter module and the filtering processing value of the second low-pass filter module are consistent;

[0014] Arctan / Arccot ​​module, used to perform inverse tangent transformation and inverse cotangent transformation decoupling on Psin value and Pcos value, so as to obtain the basic angle value of permanent magnet synchronous motor rotor;

[0015] The phase-locked loop module is used to perform closed-loop processing on the basic angle value of the permanent magnet synchronous motor rotor, so as to obtain the actual angle value of the permanent magnet synchronous motor rotor.

[0016] Furthermore, the linear Hall sensor generates a SIN value signal which enters the first low-pass filter module. The transfer function of the first low-pass filter module is 1 / (r*s+1), where r is a constant and the parameters are adjusted according to different filtering effects.

[0017] Furthermore, the linear Hall sensor generates a COS value signal which enters the second low-pass filter module, and the transfer function of the second low-pass filter module is 1 / (Kp*r*s+Ki+1), wherein r is a constant, and Kp and Ki are parameters of the PI module.

[0018] Furthermore, the first maximum and minimum value acquisition module uses MAX(SIN) and MIN(SIN) functions to capture the maximum and minimum values ​​of SIN after low-pass filtering to obtain Maxsin and Minsin;

[0019] The second maximum and minimum value acquisition module uses the MAX(COS) and MIN(COS) functions to capture the maximum and minimum values ​​of COS after low-pass filtering to obtain Maxcos and Mincos.

[0020] Furthermore, the amplitude compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, takes the filtering processing value of the first low-pass filter module as a reference, calculates the amplitude compensation coefficient Ka=(Maxsin-Minsin) / (Maxcos-Mincos), and uses the formula Acos=Ka*Lpfsin to perform amplitude compensation.

[0021] Furthermore, the bias compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, and uses the filtering processing value of the first low-pass filter module as a reference to calculate the bias compensation coefficient Kb=((Maxsin-Minsin)-(Maxcos-Mincos)) / (2*Ka), and uses the formula Ocos=Kb*Acos to perform phase compensation.

[0022] Furthermore, the phase compensation module forms an orthogonal error value by comparing the orthogonal characteristics of the filtering value of the first low-pass filter module and the Ocos value. The calculation expression of the orthogonal error value is:

[0023] Perr=1–(Lpfsin^2+Ocos^2)

[0024] Wherein, Perr is the orthogonal error value, and Lpfsin is the filtering processing value of the first low-pass filter module.

[0025] Further, in the Arctan / Arccot ​​module, the Psin and Pcos signals, which are orthogonal curves, are used to calculate the basic angle value Theta of the permanent magnet synchronous motor rotor through the Arctan() function at a mechanical angle of (0-45)°∪(135-180)°∪(180-225)°∪(315-360)°;

[0026] When the mechanical angle is (45-90)°∪(90-135)°∪(225-270)°∪(270-315)°, the basic angle value Theta of the permanent magnet synchronous motor rotor is calculated by the Arccot() function.

[0027] Furthermore, the phase-locked loop module performs angle shaping and delay compensation on the basic angle value of the permanent magnet synchronous motor rotor according to the low phase delay characteristics of the phase-locked loop.

[0028] Further, the first low-pass filter module is respectively connected to the linear Hall sensor and the first maximum and minimum value acquisition module, the second low-pass filter module is respectively connected to the linear Hall sensor and the second maximum and minimum value acquisition module, the output end of the first maximum and minimum value acquisition module is respectively connected to the amplitude compensation module, the bias compensation module and the phase compensation module, the output end of the second maximum and minimum value acquisition module is connected to the amplitude compensation module, the amplitude compensation module, the bias compensation module and the phase compensation module are connected in sequence, the phase compensation module is connected to the second low-pass filter module through the PI module, the phase compensation module is also connected to the Arctan / Arccot ​​module, and the Arctan / Arccot ​​module is also connected to the phase-locked loop module.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] Since the linear Hall output signal has errors such as amplitude, DC offset, orthogonality, these errors will cause abnormal torque pulsation and current imbalance during the actual motor operation, and may even cause current loop saturation and overcurrent.

[0031] Therefore, in order to better solve the above problems, a comprehensive compensation method for angle error is proposed. In this method, the SIN and COS signals are output by a linear Hall sensor, wherein the SIN signal is input into the first low-pass filter module, the first low-pass filter module performs a first-order low-pass filtering process on the SIN signal, and the output of the first low-pass filter module is input into the first maximum and minimum value acquisition module to obtain the maximum value Maxsin, the minimum value Minsin and the value Lpfsin after filtering of the SIN signal. The COS signal is input into the second low-pass filter module, the second low-pass filter module has a parameter port for adjusting the filtering performance, the second low-pass filter module performs a first-order low-pass filtering process on the COS signal, and the output of the second low-pass filter module is input into the second maximum and minimum value acquisition module to obtain the maximum value Maxcos, the minimum value Mincos and the value Lpfcos after filtering of the COS signal. The outputs of the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module are connected to the amplitude compensation module to obtain the value Acos after amplitude compensation. The output of the amplitude compensation module is connected to the bias compensation module to obtain the value Ocos after bias compensation. The outputs of the bias compensation module and the first maximum and minimum value acquisition module are connected to the phase compensation module, and the phase compensation module outputs the phase compensation value Perr, the phase-compensated Psin, and the phase-compensated Pcos. The output phase compensation value Perr of the phase compensation module is connected to the PI adjustment module to adjust the adjustable filtering performance parameters of the second low-pass filter module. The phase-compensated Psin and the phase-compensated Pcos of the phase compensation module are connected to the Arctan / Arccot ​​module, and Theta is obtained after sine-cotangent transformation. Theta is connected to the phase-locked loop module to obtain the final angle value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of an angle error compensation device for a linear Hall encoder of a permanent magnet synchronous motor provided in an embodiment of the present invention;

[0033] Figure 2 The present invention provides a schematic diagram of the operation flow of a linear Hall encoder angle error compensation device for a permanent magnet synchronous motor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0038] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0040] Example 1

[0041] like Figure 1 and 2 As shown, this embodiment provides a permanent magnet synchronous motor linear Hall encoder angle error compensation device, comprising:

[0042] The first low-pass filter module is used to perform a first-order low-pass filter on the SIN signal of the linear Hall sensor, and output a SIN signal with phase delay and high-frequency components filtered out;

[0043] The first maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the SIN signal generated by the first low-pass filter module;

[0044] The second low-pass filter module is used to perform a first-order low-pass filter on the COS signal of the linear Hall sensor, and output a COS signal with a phase delay and high-frequency components filtered out. The second low-pass filter module has a parameter port for adjusting the filtering performance;

[0045] The second maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the COS signal generated by the second low-pass filter module;

[0046] An amplitude compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform amplitude compensation on the filtered value of the second low-pass filter module to obtain an Acos value;

[0047] The bias compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform bias compensation on the Acos value to obtain the Ocos value;

[0048] A phase compensation module is used to compare the orthogonal characteristics of the filter processing value of the first low-pass filter module and the Ocos value to form an orthogonal error value, perform phase compensation on the filter processing value of the first low-pass filter module to obtain a Psin value, and perform phase compensation on the Ocos value to obtain a Pcos value;

[0049] A PI module, used to perform PI adjustment on the filtering performance of the second low-pass filter module according to the orthogonal error value, so that the phase of the filtering processing value of the first low-pass filter module and the filtering processing value of the second low-pass filter module are consistent;

[0050] Arctan / Arccot ​​module, used to perform inverse tangent transformation and inverse cotangent transformation decoupling on Psin value and Pcos value, so as to obtain the basic angle value of permanent magnet synchronous motor rotor;

[0051] The phase-locked loop module is used to perform closed-loop processing on the basic angle value of the permanent magnet synchronous motor rotor, so as to obtain the actual angle value of the permanent magnet synchronous motor rotor.

[0052] Specifically, the linear Hall sensor generates a SIN value signal which enters the first low-pass filter module. The transfer function of the first low-pass filter module is 1 / (r*s+1), where r is a constant and the parameters are adjusted according to different filtering effects.

[0053] The linear Hall sensor generates a COS value signal that enters the second low-pass filter module. The transfer function of the second low-pass filter module is 1 / (Kp*r*s+Ki+1), where r is a constant. Kp and Ki are parameters of the PI module, which directly affect the cutoff frequency and phase delay of the second low-pass filter module.

[0054] First, obtain the maximum and minimum value module, use the MAX(SIN) and MIN(SIN) functions to capture the maximum and minimum values ​​of SIN after low-pass filtering, and obtain Maxsin and Minsin;

[0055] The second maximum and minimum value acquisition module uses the MAX(COS) and MIN(COS) functions to capture the maximum and minimum values ​​of COS after low-pass filtering to obtain Maxcos and Mincos.

[0056] The amplitude compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, and uses the filtered processing value Lpfsin of the first low-pass filter module as a reference to calculate the amplitude compensation coefficient Ka=(Maxsin-Minsin) / (Maxcos-Mincos), and uses the formula Acos=Ka*Lpfsin to perform amplitude compensation.

[0057] The bias compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, and takes the filtered processing value Lpfsin of the first low-pass filter module as a reference to calculate the bias compensation coefficient Kb=((Maxsin-Minsin)-(Maxcos-Mincos)) / (2*Ka), and uses the formula Ocos=Kb*Acos to perform phase compensation.

[0058] The phase compensation module forms an orthogonal error value by comparing the orthogonal characteristics of the filtering value Lpfsin and the Ocos value of the first low-pass filter module. The calculation expression of the orthogonal error value is:

[0059] Perr=1–(Lpfsin^2+Ocos^2)

[0060] Wherein, Perr is the orthogonal error value, and Lpfsin is the filtering processing value of the first low-pass filter module.

[0061] Perr is input into the PI module as the error amount and adjusted to obtain the second low-pass filter module, thereby dynamically adjusting to make Psin and Pcos mutually orthogonal curves.

[0062] In the Arctan / Arccot ​​module, the Psin and Pcos signals of mutually orthogonal curves are used to calculate the basic angle value Theta of the permanent magnet synchronous motor rotor through the Arctan() function at a mechanical angle of (0-45)°∪(135-180)°∪(180-225)°∪(315-360)°;

[0063] When the mechanical angle is (45-90)°∪(90-135)°∪(225-270)°∪(270-315)°, the basic angle value Theta of the permanent magnet synchronous motor rotor is calculated by the Arccot() function.

[0064] The basic angle value of the permanent magnet synchronous motor rotor Theta is input into the phase-locked loop module. According to the low phase delay characteristics of the phase-locked loop, the angle shaping and delay compensation of Theta can be performed. This method can effectively compensate for the angle errors caused by these three situations, thereby obtaining a more accurate actual angle value.

[0065] In this embodiment, the connection relationship between the various components of the above-mentioned device is that the first low-pass filter module is respectively connected to the linear Hall sensor and the first maximum and minimum value acquisition module, the second low-pass filter module is respectively connected to the linear Hall sensor and the second maximum and minimum value acquisition module, the output end of the first maximum and minimum value acquisition module is respectively connected to the amplitude compensation module, the bias compensation module and the phase compensation module, the output end of the second maximum and minimum value acquisition module is connected to the amplitude compensation module, the amplitude compensation module, the bias compensation module and the phase compensation module are connected in sequence, the phase compensation module is connected to the second low-pass filter module through the PI module, the phase compensation module is also connected to the Arctan / Arccot ​​module, and the Arctan / Arccot ​​module is also connected to the phase-locked loop module.

[0066] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A permanent magnet synchronous motor linear Hall encoder angle error compensation device, characterized in that: include: The first low-pass filter module is used to perform a first-order low-pass filter on the SIN signal of the linear Hall sensor, and output a SIN signal with phase delay and high-frequency components filtered out; A first maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the SIN signal generated by the first low-pass filter module; A second low-pass filter module, used for performing a first-order low-pass filter on the COS signal of the linear Hall sensor, and outputting a COS signal with a phase delay and high-frequency components filtered out, wherein the second low-pass filter module has a parameter port for adjusting the filtering performance; The second maximum and minimum value acquisition module is used to record the maximum value, minimum value and filtering value of the COS signal generated by the second low-pass filter module; An amplitude compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform amplitude compensation on the filtered value of the second low-pass filter module to obtain an Acos value; The bias compensation module is used to compare the maximum and minimum values ​​output by the first maximum and minimum value acquisition module and the second maximum and minimum value acquisition module, and perform bias compensation on the Acos value to obtain the Ocos value; A phase compensation module is used to compare the orthogonal characteristics of the filter processing value of the first low-pass filter module and the Ocos value to form an orthogonal error value, perform phase compensation on the filter processing value of the first low-pass filter module to obtain a Psin value, and perform phase compensation on the Ocos value to obtain a Pcos value; A PI module, used for performing PI adjustment on the filtering performance of the second low-pass filter module according to the orthogonal error value, so that the phase of the filtering processing value of the first low-pass filter module and the filtering processing value of the second low-pass filter module are consistent; Arctan / Arccot ​​module, used to perform inverse tangent transformation and inverse cotangent transformation decoupling on Psin value and Pcos value, so as to obtain the basic angle value of permanent magnet synchronous motor rotor; A phase-locked loop module, used for performing closed-loop processing on the basic angle value of the permanent magnet synchronous motor rotor, so as to obtain the actual angle value of the permanent magnet synchronous motor rotor; The phase compensation module forms an orthogonal error value by comparing the orthogonal characteristics of the filtering value of the first low-pass filter module and the Ocos value. The calculation expression of the orthogonal error value is: Perr=1–(Lpfsin^2+Ocos^2) Where Perr is the orthogonal error value, and Lpfsin is the filtering processing value of the first low-pass filter module; Perr is input into the PI module as the error amount and adjusted to obtain the second low-pass filter module, thereby dynamically adjusting the Psin value and the Pcos value to form orthogonal curves.

2. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: The linear Hall sensor generates a SIN value signal which enters the first low-pass filter module. The transfer function of the first low-pass filter module is 1 / (r*s+1), where r is a constant and the parameters are adjusted according to different filtering effects.

3. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: The linear Hall sensor generates a COS value signal which enters the second low-pass filter module. The transfer function of the second low-pass filter module is 1 / (Kp*r*s+Ki+1), where r is a constant, and Kp and Ki are parameters of the PI module.

4. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: The first maximum and minimum value acquisition module uses the MAX(SIN) and MIN(SIN) functions to capture the maximum and minimum values ​​of SIN after low-pass filtering to obtain Maxsin and Minsin; The second maximum and minimum value acquisition module uses the MAX(COS) and MIN(COS) functions to capture the maximum and minimum values ​​of COS after low-pass filtering to obtain Maxcos and Mincos.

5. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 4, characterized in that: The amplitude compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, takes the filtering processing value of the first low-pass filter module as a reference, calculates the amplitude compensation coefficient Ka=(Maxsin-Minsin) / (Maxcos-Mincos), and uses the formula Acos=Ka*Lpfsin to perform amplitude compensation.

6. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 4, characterized in that: The bias compensation module obtains the values ​​of Maxsin, Minsin, Maxcos, and Mincos, and uses the filtering processing value of the first low-pass filter module as a reference to calculate the bias compensation coefficient Kb=((Maxsin-Minsin)-(Maxcos-Mincos)) / (2*Ka), and uses the formula Ocos=Kb*Acos to perform phase compensation.

7. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: In the Arctan / Arccot ​​module, the Psin and Pcos signals, which are orthogonal curves, are used to calculate the basic angle value Theta of the permanent magnet synchronous motor rotor through the Arctan() function at a mechanical angle of (0-45)°∪(135-180)°∪(180-225)°∪(315-360)°; When the mechanical angle is (45-90)°∪(90-135)°∪(225-270)°∪(270-315)°, the basic angle value Theta of the permanent magnet synchronous motor rotor is calculated by the Arccot() function.

8. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: The phase-locked loop module performs angle shaping and delay compensation on the basic angle value of the permanent magnet synchronous motor rotor according to the low phase delay characteristic of the phase-locked loop.

9. The angle error compensation device of a linear Hall encoder of a permanent magnet synchronous motor according to claim 1, characterized in that: The first low-pass filter module is respectively connected to the linear Hall sensor and the first maximum and minimum value acquisition module, the second low-pass filter module is respectively connected to the linear Hall sensor and the second maximum and minimum value acquisition module, the output end of the first maximum and minimum value acquisition module is respectively connected to the amplitude compensation module, the bias compensation module and the phase compensation module, the output end of the second maximum and minimum value acquisition module is connected to the amplitude compensation module, the amplitude compensation module, the bias compensation module and the phase compensation module are connected in sequence, the phase compensation module is connected to the second low-pass filter module through the PI module, the phase compensation module is also connected to the Arctan / Arccot ​​module, and the Arctan / Arccot ​​module is also connected to the phase-locked loop module.

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