A motor rotor angle determination system and method based on sliding film observer

Abstract

The present invention relates to a motor rotor angle determination system and method based on a synovial observer. By setting a synovial observer, a compensation device and a processing module, the synovial observer is used to obtain a rotor rotation angle prediction value and an angular velocity prediction value of a controlled motor in real time. Subsequently, the compensation device obtains the arctangent value of the ratio of the stator d-axis voltage to the q-axis voltage, and uses a motor mathematical model voltage equation to obtain the arctangent value of the ratio of the d-axis theoretical output voltage to the q-axis theoretical output voltage according to the stator d-axis current and the q-axis current. Then, a proportional-integral control algorithm is used to obtain a compensation angle according to the difference between the two obtained arctangent values. This not only improves the accuracy of the compensation angle, but also reduces the algorithm complexity, saves energy consumption, and enables the result obtained by the processing module to have high-precision characteristics.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a system and method for determining a motor rotor angle based on a sliding film observer. Background Art

[0002] The sliding film observer plays a key role in the sensorless drive technology of permanent magnet synchronous motor (PMSM). It can obtain the speed and position of the motor rotor by detecting the current and voltage of the motor. In the process of obtaining the speed and position of the motor rotor, the sliding film observer needs to extract the back electromotive force. The way to extract the back electromotive force is to embed a low-pass filter, which will cause phase delay, resulting in a large deviation in the position of the motor rotor, which ultimately affects the drive control performance of the motor.

[0003] In order to solve the problem of large deviation in the motor rotor position obtained due to phase delay, an angle compensation method is usually used, that is, a compensation angle is added on the basis of the rotor position information obtained by the sliding film observer to overcome the phase delay.

[0004] However, in the prior art, the compensation angle is usually acquired based on the cutoff frequency of the low-pass filter and the current fundamental frequency of the motor rotor speed. When the motor is at different speeds and different load states, the compensation angle is inaccurate, thereby reducing the motor control efficiency. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to overcome the technical defect of inaccurate compensation angle in the existing sensorless drive technology. In order to overcome the defects of the above-mentioned prior art, the present invention provides a motor rotor angle determination system and method based on a synovial film observer, including a motor rotor angle determination system based on a synovial film observer and a motor rotor angle determination method based on a synovial film observer.

[0006] The present invention provides a motor rotor angle determination system based on a sliding film observer, comprising:

[0007] A synovial observer is configured to obtain a predicted rotation angle and an angular velocity of a rotor of the controlled motor in real time by measuring a back electromotive force of the stator of the controlled motor;

[0008] A compensation device is configured to obtain an inverse tangent value of a ratio of a d-axis voltage to a q-axis voltage of the stator, and to obtain an inverse tangent value of a ratio of a theoretical output voltage of the d-axis to a theoretical output voltage of the q-axis according to a d-axis current and a q-axis current of the stator using a voltage equation of a mathematical model of a motor, and then to obtain a compensation angle according to a difference between the two obtained inverse tangent values ​​using a proportional-integral control algorithm;

[0009] a processing module, configured to receive in real time the predicted value of the rotor rotation angle obtained by the synovial observer and the compensation angle obtained by the compensation device, take the sum of the predicted value of the rotor rotation angle and the compensation angle as the rotation angle of the measured controlled motor, and then obtain the angular velocity and angular acceleration of the measured controlled motor according to the rotation angle by numerical differentiation;

[0010] The compensation device is electrically connected to the synovial membrane observer, and the processing module is electrically connected to the synovial membrane observer and the compensation device respectively.

[0011] The motor rotor angle determination system based on the synovial observer disclosed in the present invention aims at the technical problem of the present invention. By setting the synovial observer, the compensation device and the processing module, the synovial observer is used to obtain the rotor rotation angle prediction value and the angular velocity prediction value of the controlled motor in real time. Then the compensation device obtains the arctangent value of the ratio of the stator d-axis voltage to the q-axis voltage, and the motor mathematical model voltage equation is used to obtain the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator, and then the proportional integral control algorithm is used to obtain the compensation angle according to the two obtained arctangent values. Since the motor mathematical model is used in the process of obtaining the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and the compensation angle is obtained according to the two obtained arctangent values ​​by the proportional integral control algorithm, and the motor mathematical model algorithm is based on the motor mathematical model algorithm, which is concise and accurately described, and the obtained compensation angle is based on the voltage collected in reality, so that not only the accuracy of the compensation angle is improved, but also the algorithm complexity is reduced, and energy consumption is saved. Moreover, on this basis, combined with the setting of the processing module, it is not only ensured that the hysteresis compensation angle of the synovial observer can be obtained by automatic adjustment, thus eliminating the need for manual debugging by experienced engineers, greatly reducing the difficulty and cost of debugging, but also, due to the improved accuracy of the compensation angle, the problem of motor control performance degradation caused by inaccurate compensation angle is also reduced, further reducing maintenance costs.

[0012] In a possible implementation manner, the compensation device includes:

[0013] a Clarke transformer configured to perform a Clarke transform;

[0014] a Park transformer configured to perform a Park transformation;

[0015] A current-voltage acquisition unit is configured to acquire the three-phase current and three-phase voltage of the stator in real time;

[0016] A proportional-integral regulator is configured to execute a proportional-integral control algorithm;

[0017] A central processing unit, configured to control the Clark converter, the Park converter, and the proportional-integral regulator to operate in real time according to the three-phase current and the three-phase voltage to obtain the compensation angle;

[0018] The central processor is electrically connected to the synovial observer, the current-voltage acquisition unit, the Clark converter, the Park converter, the proportional-integral regulator, and the processing module respectively;

[0019] Furthermore, the three-phase voltage of the stator can be obtained through the current-voltage acquisition unit, and then the d-axis voltage and the q-axis voltage can be obtained by combining the settings of the Clark converter and the Park converter, and then the inverse tangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis can be obtained. Finally, the proportional-integral regulator can be called to obtain the compensation angle according to the two obtained inverse tangent values ​​through the proportional-integral control algorithm, thereby ensuring the accuracy and efficiency of the obtained compensation angle.

[0020] In a possible implementation, the current-voltage acquisition unit includes a three-phase voltage and current sensor; this solution can directly measure the three-phase alternating current and voltage and convert them into a standard DC signal output, thereby further improving the accuracy of the compensation device in obtaining the compensation angle.

[0021] In a possible implementation manner, the central processor is configured to obtain the compensation angle by executing the following steps:

[0022] A1: Mark the current moment as the initial moment, and retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and retrieve the predicted value of the rotor rotation angle and the predicted value of the angular velocity obtained by the synovial observer;

[0023] A2: calling the Clarke converter to respectively perform Clarke transformation on the currently retrieved three-phase current to obtain a first current transformation result and to perform Clarke transformation on the currently retrieved three-phase voltage to obtain a first voltage transformation result;

[0024] A3: calling the Park transformer to perform a Park transformer on the first voltage transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis voltage and the q-axis voltage;

[0025] A4: Calculate the arctangent value of the ratio of the d-axis voltage to the q-axis voltage, and use the arctangent value as the first angle;

[0026] A5: calling the Park transformer to perform a Park transformer on the first current transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis current and the q-axis current;

[0027] A6: Substitute the d-axis current, the q-axis current, and the currently retrieved angular velocity prediction value into the voltage equation of the motor mathematical model to obtain the theoretical output voltage of the d-axis and the theoretical output voltage of the q-axis;

[0028] A7: Calculate the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and use the arctangent value as the second angle;

[0029] A8: subtracting the first angle from the second angle to obtain an error value;

[0030] A9: Determine whether the time interval between this moment and the last time the initial moment was marked is not less than one sampling period;

[0031] If yes, proceed to the next step;

[0032] If not, continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2;

[0033] A10: Retrieve all error values ​​obtained in step A8 from the time when the initial moment was marked last time to the present moment, and call the proportional-integral regulator to operate according to these error values ​​to obtain the compensation angle;

[0034] A11: Mark this moment as the initial moment, and continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2;

[0035] This scheme uses the voltage equation of the motor mathematical model to obtain the theoretical output voltage of the d-axis and the theoretical output voltage of the q-axis, and obtains the second angle. The error value distribution is obtained by combining the first angle based on the actual output, and the output compensation angle is calculated through a proportional-integral regulator closed loop, thereby further improving the accuracy of the compensation angle.

[0036] In a possible implementation, in step A2:

[0037] The formula for obtaining the first current conversion result is as follows:

[0038] ,

[0039] In the formula,

[0040] represents the first current transformation result;

[0041] Represents the three-phase current currently retrieved;

[0042] The formula for obtaining the first voltage conversion result is as follows:

[0043] ,

[0044] In the formula,

[0045] represents the first voltage transformation result;

[0046] Represents the currently retrieved three-phase voltage;

[0047] This solution can not only speed up the transformation time, but also make the transformation reasonable and capture the transformation results in a shorter time, so that the rate of obtaining the compensation angle is further improved.

[0048] In a possible implementation, in step A3:

[0049] The formula for obtaining the d-axis voltage and the q-axis voltage is as follows:

[0050] ,

[0051] In the formula,

[0052] represents the d-axis voltage;

[0053] represents the q-axis voltage;

[0054] Represents the currently retrieved predicted value of the rotor rotation angle;

[0055] This solution only performs angle rotation on the voltage vector without changing the norm, thereby not changing the voltage structure, and obtains the transformation result relatively quickly, thereby improving the transformation efficiency.

[0056] In a possible implementation, in step A5:

[0057] The formula of the voltage equation of the motor mathematical model is as follows:

[0058] ,

[0059] In the formula,

[0060] represents the theoretical output voltage of the d-axis;

[0061] represents the theoretical output voltage of the q-axis;

[0062] Represents the phase resistance of the controlled motor;

[0063] Represents the currently retrieved angular velocity prediction value;

[0064] represents the inductance of the d-axis;

[0065] represents the inductance of the q-axis;

[0066] represents the d-axis current;

[0067] represents the q-axis current;

[0068] represents the permanent magnet flux of the controlled motor;

[0069] The mathematical model corresponding to this scheme has the advantages of simple equation structure, small amount of calculation and low computational complexity. The obtained theoretical output voltage of the d-axis and the theoretical output voltage of the q-axis are highly accurate and have small errors, thereby further ensuring the accuracy of the obtained compensation angle and alleviating the technical drawbacks of delayed control of the controlled motor.

[0070] In a possible implementation, in step A9:

[0071] The formula for obtaining the compensation angle is as follows:

[0072] ,

[0073] In the formula,

[0074] represents the compensation angle;

[0075] represents proportional gain;

[0076] represents the error function determined by all error values ​​obtained in the period from the last time the initial moment was marked in step A8 to the present moment;

[0077] represents the integral gain;

[0078] represents the time when said initial moment was last marked;

[0079] represents the sampling period;

[0080] The proportional and integral control algorithm corresponding to this solution can improve the processing efficiency of the proportional and integral regulator for input, obtain the compensation angle more quickly and accurately, and thus greatly improve the operating efficiency.

[0081] Another technical solution of the present invention is to provide a method for determining the motor rotor angle based on a sliding film observer, the method comprising the following steps:

[0082] S1: measuring the back electromotive force of the stator of the controlled motor through a sliding film observer to obtain a predicted value of the rotor rotation angle and the predicted value of the angular velocity of the controlled motor;

[0083] S2: obtaining the inverse tangent value of the ratio of the d-axis voltage to the q-axis voltage of the stator through a compensation device, and obtaining the inverse tangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator using a voltage equation of a motor mathematical model;

[0084] S3: obtaining a compensation angle according to the difference between the two arctangent values ​​obtained in step S2 by the compensation device using a proportional-integral control algorithm;

[0085] S4: receiving the predicted value of the rotor rotation angle obtained in step S1 and the compensation angle obtained in step S3 through a processing module, and taking the sum of the predicted value of the rotor rotation angle and the compensation angle as the rotation angle of the measured controlled motor;

[0086] S5: Obtaining the angular velocity and angular acceleration of the controlled motor according to the rotation angle by numerical differentiation through the processing module.

[0087] The method disclosed by the present invention obtains the predicted value of the rotor rotation angle and the predicted value of the angular velocity of the controlled motor by using a sliding film observer through step S1, then obtains the arctangent value of the ratio of the stator d-axis voltage to the q-axis voltage by using a compensation device through steps S2 and S3, and obtains the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator by using the motor mathematical model voltage equation, and then obtains the compensation angle according to the two obtained arctangent values ​​by using a proportional integral control algorithm. Since the motor mathematical model is used in the process of obtaining the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and the compensation angle is obtained according to the two obtained arctangent values ​​by using a proportional integral control algorithm, and the motor mathematical model algorithm is concise and accurately described, and the obtained compensation angle is based on the voltage collected in reality, so that not only the accuracy of the compensation angle is improved, but also the algorithm complexity is reduced, and energy consumption is saved. Subsequently, on this basis, steps S4 and S5 are combined to utilize the processing module to obtain the angular velocity and angular acceleration of the controlled motor, which not only ensures that the hysteresis compensation angle of the synovial observer can be obtained by automatic adjustment, and thus does not require manual debugging by experienced engineers, greatly reducing the difficulty and cost of debugging. Moreover, since the accuracy of the compensation angle is improved, the problem of motor control performance degradation caused by inaccurate compensation angle is also reduced, further reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 A schematic diagram of the structure of a motor rotor angle determination system based on a sliding film observer disclosed in an embodiment of the present application;

[0089] Figure 2 It is an operation flow chart of the central processing unit disclosed in the embodiment of this application;

[0090] Figure 3 This is a flow chart of the method disclosed in the embodiments of this application. DETAILED DESCRIPTION

[0091] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0092] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "electrical connection" and "electrical connection relationship" should be understood in a broad sense, that is, referring to a connection method with an electrical relationship, for example, it can be a circuit connection achieved through a wire, or it can be an electrical connection achieved through a radio signal channel (channel), or a combination of the two. In addition, "electrical connection" and "electrical connection relationship" can be based on a mechanical connection (such as a wire set in a connection key); it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances. The communication connection means that the two connected parties have a signal transmission relationship, which can be an electrical connection through equipment such as a cable, or communication achieved through a channel.

[0093] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0094] See also Figure 1 and Figure 2 As shown, the embodiment of the present application discloses a motor rotor angle determination system based on a sliding film observer, and its structural schematic diagram is shown in Figure 1 As shown, the system includes a synovial observer, a compensation device and a processing module, wherein the compensation device is electrically connected to the synovial observer, and the processing module is electrically connected to the synovial observer and the compensation device respectively.

[0095] The synovial observer used in this embodiment is a field-oriented control (FOC) type synovial observer. In this system, it is configured to obtain the rotation angle prediction value and angular velocity prediction value of the rotor of the controlled motor in real time by measuring the back electromotive force of the stator of the controlled motor. The compensation device is configured to obtain the arc tangent value of the ratio of the d-axis voltage to the q-axis voltage of the stator, and obtain the arc tangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator using the voltage equation of the motor mathematical model, and then obtain the compensation angle according to the difference between the two obtained arc tangent values ​​through the proportional integral control algorithm. The processing module is configured to receive the rotor rotation angle prediction value obtained by the synovial observer and the compensation angle obtained by the compensation device in real time, and use the sum of the rotor rotation angle prediction value and the compensation angle as the rotation angle of the controlled motor, and then obtain the angular velocity and angular acceleration of the controlled motor according to the rotation angle through numerical differentiation.

[0096] Please continue to see Figure 1As shown, in this embodiment, the compensation device includes a Clarke converter, a Park converter, a current-voltage acquisition unit, a proportional-integral regulator and a central processing unit, wherein the central processing unit is electrically connected to the synovial observer, the current-voltage acquisition unit, the Clarke converter, the Park converter, and the proportional-integral regulator respectively.

[0097] In the compensation device, the Clarke transformer is configured to perform a Clarke transformation, and the transformation formula of the Clarke transformation performed by the Clarke transformer is as follows:

[0098] ,

[0099] In the formula,

[0100] ;

[0101] Represents the output of Clarke transform;

[0102] Represents the 3D input vector on which the Clarke transform is to be performed.

[0103] In the compensation device, the Park transformer is configured to perform a Park transformation, and the transformation formula of the Park transformation performed by the Park transformer is as follows:

[0104] ,

[0105] In the formula,

[0106] ;

[0107] represents the rotation angle;

[0108] Represents the output of Park transform;

[0109] Represents the two-dimensional input vector on which the Park transform is to be performed.

[0110] In the compensation device, the current-voltage acquisition unit is configured to acquire the three-phase current and three-phase voltage of the stator in real time. Specifically in this embodiment, the current-voltage acquisition unit uses a three-phase voltage and current sensor, which can directly measure the three-phase alternating current and three-phase alternating voltage of the rotor of the controlled motor, and convert them into standard DC signal output, thereby further improving the efficiency and accuracy of the compensation device in acquiring the compensation angle.

[0111] In the compensation device, the proportional-integral regulator is configured to execute a proportional-integral control algorithm, and the proportional-integral control algorithm executed by the regulator is as follows:

[0112] ,

[0113] In the formula,

[0114] Represents the output result of the proportional integral regulator;

[0115] represents the error function;

[0116] represents the proportional gain. For this embodiment, in order to make the compensation angle more accurate, the proportional gain value is 0.5;

[0117] represents the integral gain. In this embodiment, the integral gain value is 0.02.

[0118] In the compensation device, the central processor is configured to control the Clark converter, Park converter, and proportional integral regulator in real time according to the three-phase current and three-phase voltage to obtain the compensation angle. Figure 2 As shown, the central processing unit is configured to obtain the compensation angle by executing the following steps:

[0119] A1: Mark the current moment as the initial moment, and retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit at this moment, and retrieve the predicted value of the rotor rotation angle and the predicted value of the angular velocity obtained by the synovial observer at this moment.

[0120] A2: Calling the Clarke converter to perform Clarke transformation on the currently retrieved three-phase current to obtain a first current transformation result and to perform Clarke transformation on the currently retrieved three-phase voltage to obtain a first voltage transformation result.

[0121] Specifically, in step A2, the central processor is configured to transmit the specific values ​​of the currently retrieved three-phase currents to the Clark converter as the input vector of the Clark converter, and then the Clark converter obtains the first current conversion result through the following formula:

[0122] ,

[0123] In the formula,

[0124] represents the first current transformation result;

[0125] Represents the three-phase current currently retrieved;

[0126] After obtaining the first current transformation result, the Clarke converter transmits the first current transformation result to the central processing unit.

[0127] In addition, in the process of obtaining the first voltage conversion result, the central processing unit is configured to transmit the specific value of the currently retrieved three-phase voltage to the Clark converter as an input vector of the Clark converter, and then the Clark converter obtains the first voltage conversion result through the following formula:

[0128] ,

[0129] In the formula,

[0130] represents the first voltage transformation result;

[0131] Represents the currently retrieved three-phase voltage;

[0132] After obtaining the first voltage transformation result, the Clarke converter transmits the first voltage transformation result to the central processing unit.

[0133] A3: Call the Park transformer to perform a Park transformer on the first voltage transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis voltage and the q-axis voltage, and use the d-axis voltage and the q-axis voltage as the second voltage transformation result.

[0134] Specifically, in step A3, the central processing unit is configured to transmit the first voltage conversion result and the currently retrieved predicted value of the rotor rotation angle to the Park converter, so that the first voltage conversion result is used as the input vector of the Park converter, and the currently retrieved predicted value of the rotor rotation angle is used as the rotation angle of the Park converter to be executed, and then the Park converter obtains the second voltage conversion result through the following formula;

[0135] ,

[0136] In the formula,

[0137] represents the d-axis voltage;

[0138] represents the q-axis voltage;

[0139] Represents the currently retrieved predicted value of the rotor rotation angle;

[0140] After obtaining the second voltage transformation result, the Park transformer transmits the second voltage transformation result to the central processing unit.

[0141] A4: Calculate the arctangent value of the ratio of the d-axis voltage to the q-axis voltage in the second voltage transformation result, and use the arctangent value as the first angle.

[0142] Specifically,

[0143] ,

[0144] In the formula, Represents the first angle.

[0145] A5: Call the Park transformer to perform a Park transformer on the first current transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis current and the q-axis current, and use the result as the second current transformation result.

[0146] Specifically, in step A5, the central processing unit is configured to transmit the first current transformation result and the currently retrieved predicted value of the rotor rotation angle to the Park converter, so that the first current transformation result is used as the input vector of the Park converter, and the currently retrieved predicted value of the rotor rotation angle is used as the rotation angle of the Park converter to be executed, and then the Park converter obtains the second current transformation result through the following formula;

[0147] ,

[0148] In the formula,

[0149] represents the d-axis current;

[0150] represents the q-axis current;

[0151] After obtaining the second current transformation result, the Park converter transmits the second current transformation result to the central processing unit.

[0152] A6: Substitute the d-axis current, q-axis current, and the currently retrieved angular velocity prediction value into the voltage equation of the motor mathematical model to obtain the theoretical output voltage of the d-axis and the theoretical output voltage of the q-axis.

[0153] Specifically, in step A6, the formula of the voltage equation of the motor mathematical model is as follows:

[0154] ,

[0155] In the formula,

[0156] Represents the theoretical output voltage of the d-axis;

[0157] Represents the theoretical output voltage of the q-axis;

[0158] Represents the phase resistance of the controlled motor;

[0159] Represents the currently retrieved angular velocity prediction value;

[0160] represents the inductance of the d-axis;

[0161] represents the inductance of the q-axis;

[0162] Represents the permanent magnet flux of the controlled motor.

[0163] A7: Calculate the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and use the arctangent value as the second angle.

[0164] Specifically,

[0165] ,

[0166] In the formula, Represents the second angle.

[0167] A8: Subtract the first angle from the second angle to obtain an error value.

[0168] Specifically, if the first angle obtained in this iteration is , the second angle is , then through The result obtained is the error value in this round of iteration.

[0169] A9: Determine whether the time interval between this moment and the last time the initial time was marked is not less than one sampling period;

[0170] If yes, proceed to the next step;

[0171] If not, continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2.

[0172] A10: Retrieve all error values ​​obtained from step A8 from the last time the initial moment was marked to the present moment, and call the proportional-integral regulator to operate according to these error values ​​to obtain the compensation angle.

[0173] Specifically, in step A10, the central processor is configured to transmit the specific time value of the last marked initial time and all error values ​​obtained during the period from the last marked initial time to the present time to the proportional integral regulator as the input of the proportional integral regulator, and then the proportional integral regulator obtains the compensation angle through the following formula:

[0174] ,

[0175] In the formula,

[0176] represents the compensation angle;

[0177] represents the error function determined by all error values ​​obtained in step A8 from the time when the initial time was last marked to the present time;

[0178] represents the time when the initial moment was last marked;

[0179] represents the sampling period;

[0180] After obtaining the compensation angle, the proportional-integral regulator transmits the compensation angle to the central processing unit.

[0181] A11: Record the value at this moment, mark this moment as the initial moment, and continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2.

[0182] A method for using the motor rotor angle determination system based on the sliding film observer in this embodiment will be further disclosed below. Figure 3 As shown, the method comprises the following steps:

[0183] S1: The back electromotive force of the stator of the controlled motor is measured by a sliding film observer to obtain the predicted value of the rotor rotation angle and the predicted value of the angular velocity of the controlled motor.

[0184] S2: Obtain the inverse tangent value of the ratio of the stator d-axis voltage to the q-axis voltage through the compensation device, and use the motor mathematical model voltage equation to obtain the inverse tangent value of the ratio of the d-axis theoretical output voltage to the q-axis theoretical output voltage according to the stator d-axis current and q-axis current.

[0185] S3: Obtain the compensation angle according to the difference between the two arctangent values ​​obtained in step S2 by using a proportional-integral control algorithm through the compensation device.

[0186] S4: receiving the predicted value of the rotor rotation angle obtained in step S1 and the compensation angle obtained in step S3 through the processing module, and taking the sum of the predicted value of the rotor rotation angle and the compensation angle as the rotation angle of the controlled motor.

[0187] S5: Obtain the angular velocity and angular acceleration of the controlled motor according to the rotation angle by numerical differentiation through the processing module.

[0188] The motor rotor angle determination system based on the synovial observer disclosed in this embodiment is provided with a synovial observer, a compensation device and a processing module, wherein the compensation device includes a Clark converter, a Park converter, a current-voltage acquisition unit, a proportional-integral regulator and a central processing unit. The synovial observer obtains the rotor rotation angle prediction value and the angular velocity prediction value of the controlled motor in real time. The central processing unit of the compensation device obtains the arctangent value of the ratio of the stator d-axis voltage to the q-axis voltage, and obtains the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator by using the motor mathematical model voltage equation, and then obtains the compensation angle according to the obtained two arctangent values ​​by using the proportional-integral regulator and the proportional-integral control algorithm. Since the motor mathematical model is used in the process of obtaining the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and the compensation angle is obtained according to the obtained two arctangent values ​​by using the proportional-integral control algorithm, and the motor mathematical model algorithm is concise and accurately described, and the obtained compensation angle is based on the voltage actually collected, so that not only the accuracy of the compensation angle is improved, but also the algorithm complexity is reduced, and energy consumption is saved. Moreover, on this basis, combined with the setting of the processing module, it is not only ensured that the hysteresis compensation angle of the synovial observer can be obtained by automatic adjustment, thus eliminating the need for manual debugging by experienced engineers, greatly reducing the difficulty and cost of debugging, but also, due to the improved accuracy of the compensation angle, the problem of motor control performance degradation caused by inaccurate compensation angle is also reduced, further reducing maintenance costs.

[0189] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description, and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0190] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0191] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A motor rotor angle determination system based on a sliding film observer, characterized in that: include: A synovial observer is configured to obtain a predicted rotation angle and an angular velocity of a rotor of the controlled motor in real time by measuring a back electromotive force of the stator of the controlled motor; A compensation device is configured to obtain an inverse tangent value of a ratio of a d-axis voltage to a q-axis voltage of the stator, and to obtain an inverse tangent value of a ratio of a theoretical output voltage of the d-axis to a theoretical output voltage of the q-axis according to a d-axis current and a q-axis current of the stator using a voltage equation of a mathematical model of a motor, and then to obtain a compensation angle according to a difference between the two obtained inverse tangent values ​​using a proportional-integral control algorithm; a processing module, configured to receive in real time the predicted value of the rotor rotation angle obtained by the synovial observer and the compensation angle obtained by the compensation device, take the sum of the predicted value of the rotor rotation angle and the compensation angle as the rotation angle of the controlled motor, and then obtain the angular velocity and angular acceleration of the controlled motor according to the rotation angle by numerical differentiation; The compensation device is configured to obtain the d-axis voltage and the q-axis voltage of the stator in the following manner: firstly, the three-phase voltage of the stator is obtained, and at the same time, the predicted value of the rotor rotation angle obtained by the sliding film observer is retrieved; then, Clarke transformation is performed on the three-phase voltage; finally, the Clarke transformation result of the three-phase voltage is performed on the Park transformation with the predicted value of the rotor rotation angle as the rotation angle to obtain the d-axis voltage and the q-axis voltage; The compensation device is electrically connected to the synovial membrane observer, and the processing module is electrically connected to the synovial membrane observer and the compensation device respectively.

2. The motor rotor angle determination system based on sliding film observer according to claim 1, characterized in that: The compensation device comprises: a Clarke transformer configured to perform a Clarke transform; a Park transformer configured to perform a Park transformation; A current-voltage acquisition unit is configured to acquire the three-phase current and three-phase voltage of the stator in real time; A proportional-integral regulator is configured to execute a proportional-integral control algorithm; A central processing unit, configured to control the Clark converter, the Park converter, and the proportional-integral regulator to operate in real time according to the three-phase current and the three-phase voltage to obtain the compensation angle; The central processing unit is electrically connected to the synovial observer, the current-voltage acquisition unit, the Clark converter, the Park converter, the proportional-integral regulator, and the processing module respectively.

3. The motor rotor angle determination system based on sliding film observer according to claim 2 is characterized in that: The current-voltage acquisition unit includes a three-phase voltage and current sensor.

4. The motor rotor angle determination system based on sliding film observer according to claim 2 or 3, characterized in that: The central processing unit is configured to obtain the compensation angle by executing the following steps: A1: Mark the current moment as the initial moment, and retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and retrieve the predicted value of the rotor rotation angle and the predicted value of the angular velocity obtained by the synovial observer; A2: calling the Clarke converter to respectively perform Clarke transformation on the currently retrieved three-phase current to obtain a first current transformation result and to perform Clarke transformation on the currently retrieved three-phase voltage to obtain a first voltage transformation result; A3: calling the Park transformer to perform a Park transformer on the first voltage transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis voltage and the q-axis voltage; A4: Calculate the arctangent value of the ratio of the d-axis voltage to the q-axis voltage, and use the arctangent value as the first angle; A5: calling the Park transformer to perform a Park transformer on the first current transformation result with the currently retrieved rotor rotation angle prediction value as the rotation angle to obtain the d-axis current and the q-axis current; A6: Substitute the d-axis current, the q-axis current, and the currently retrieved angular velocity prediction value into the voltage equation of the motor mathematical model to obtain the theoretical output voltage of the d-axis and the theoretical output voltage of the q-axis; A7: Calculate the arctangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis, and use the arctangent value as the second angle; A8: subtracting the first angle from the second angle to obtain an error value; A9: Determine whether the time interval between this moment and the last time the initial moment was marked is not less than one sampling period; If yes, proceed to the next step; If not, continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2; A10: Retrieve all error values ​​obtained in step A8 from the time when the initial moment was marked last time to the present moment, and call the proportional-integral regulator to operate according to these error values ​​to obtain the compensation angle; A11: Mark this moment as the initial moment, and continue to retrieve the three-phase current and three-phase voltage obtained by the current-voltage acquisition unit, and continue to retrieve the rotor rotation angle prediction value and angular velocity prediction value obtained by the synovial observer, and then return to execute step A2.

5. The motor rotor angle determination system based on sliding film observer according to claim 4 is characterized in that: In step A2: The formula for obtaining the first current conversion result is as follows: ， In the formula, represents the first current transformation result; Represents the three-phase current currently retrieved; The formula for obtaining the first voltage conversion result is as follows: ， In the formula, represents the first voltage transformation result; Represents the currently retrieved three-phase voltage.

6. The motor rotor angle determination system based on sliding film observer according to claim 5, characterized in that: In step A3: The formula for obtaining the d-axis voltage and the q-axis voltage is as follows: ， In the formula, represents the d-axis voltage; represents the q-axis voltage; Represents the currently retrieved predicted value of the rotor rotation angle.

7. The motor rotor angle determination system based on sliding film observer according to claim 6, characterized in that: In step A6: The formula of the voltage equation of the motor mathematical model is as follows: ， In the formula, represents the theoretical output voltage of the d-axis; represents the theoretical output voltage of the q-axis; Represents the phase resistance of the controlled motor; Represents the currently retrieved angular velocity prediction value; represents the inductance of the d-axis; represents the inductance of the q-axis; represents the d-axis current; represents the q-axis current; Represents the permanent magnet flux of the controlled motor.

8. The motor rotor angle determination system based on sliding film observer according to any one of claims 5 to 7, characterized in that: In the step A10: The formula for obtaining the compensation angle is as follows: ， In the formula, represents the compensation angle; represents proportional gain; represents the error function determined by all error values ​​obtained in the period from the last time the initial moment was marked in step A8 to the present moment; represents the integral gain; represents the time when said initial moment was last marked; represents the sampling period.

9. A method for determining the motor rotor angle based on a sliding film observer, characterized in that: The motor rotor angle determination system based on the sliding film observer according to any one of claims 1 to 8 comprises the following steps: S1: measuring the back electromotive force of the stator of the controlled motor through a sliding film observer to obtain a predicted value of the rotor rotation angle and the predicted value of the angular velocity of the controlled motor; S2: obtaining the inverse tangent value of the ratio of the d-axis voltage to the q-axis voltage of the stator through a compensation device, and obtaining the inverse tangent value of the ratio of the theoretical output voltage of the d-axis to the theoretical output voltage of the q-axis according to the d-axis current and the q-axis current of the stator using a voltage equation of a motor mathematical model; The method of obtaining the d-axis voltage and the q-axis voltage of the stator is as follows: first, the three-phase voltage of the stator is obtained by the compensation device, and the predicted value of the rotor rotation angle obtained by the sliding film observer is retrieved; then, the three-phase voltage is subjected to Clarke transformation by the compensation device; finally, the Clarke transformation result of the three-phase voltage is subjected to Park transformation by the compensation device with the predicted value of the rotor rotation angle as the rotation angle, so as to obtain the d-axis voltage and the q-axis voltage; S3: obtaining a compensation angle according to the difference between the two arctangent values ​​obtained in step S2 by the compensation device using a proportional-integral control algorithm; S4: receiving the predicted value of the rotor rotation angle obtained in step S1 and the compensation angle obtained in step S3 through a processing module, and taking the sum of the predicted value of the rotor rotation angle and the compensation angle as the rotation angle of the controlled motor; S5: Obtaining the angular velocity and angular acceleration of the controlled motor according to the rotation angle by numerical differentiation through the processing module.

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