Magnetic pole position detection method and system of motor, electronic equipment and medium

Abstract

The invention discloses a magnetic pole position detection method and system of a motor, electronic equipment and a medium, and relates to the field of motor control, in the rotating process of the motor, the position and rotating speed information of a rotor are determined in real time, and after the initial position of the rotor is determined, a positive pulse signal is injected along the current position of the rotor; then determining a corresponding relation between a rotor magnetic pole and a rotor initial position according to the q-axis current and the rotating speed of the motor after the positive pulse signal is injected, so as to determine the magnetic pole position of the rotor magnetic pole by correcting the initial position of the rotor; the magnetic pole is judged by injecting a single positive voltage pulse, so that the influence of rotor position movement on magnetic pole position identification under the condition of double pulses is avoided, the magnetic pole position can be determined under the condition of rotation of the motor, the dynamic magnetic pole identification process is effectively realized, table look-up is not needed, the process is simple, and the detection speed is high.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a method, system, electronic equipment and medium for detecting the magnetic pole position of a motor. Background Art

[0002] Permanent magnet synchronous motors have been widely used in the fields of fans and water pumps. During the free stop process or before starting, the permanent magnet motor will be dragged by external forces, and the rotor permanent magnet flux will induce a back electromotive force in the stator winding with an amplitude proportional to the motor rotor speed. In this case, it is necessary to detect the initial state of the rotor poles in the motor. For example, in the case of a speed sensorless control mode, since there is no encoder, the motor can only be restarted after the speed / position estimation is performed internally by the motor control software at startup. Therefore, how to identify the pole position in the motor to achieve accurate control of the motor has become a technical problem that needs to be solved urgently.

[0003] In the prior art, magnetic pole position identification is usually performed when the motor stops rotating, by injecting two voltage pulses into the estimated d-axis and -d-axis respectively. Generally, a voltage pulse is first injected into the estimated d-axis direction, and another voltage pulse is injected into the estimated -d-axis direction after a preset time. Then, the magnetic pole is confirmed according to the change in the current amplitude of the motor under the influence of the magnetic saturation effect. However, in this method, the second pulse needs to be injected after a period of time, and the rotor will be in a rotating state when the first voltage pulse is injected. Therefore, for a rotating motor, the movement of the rotor position during the waiting process of the second pulse will affect the accuracy of magnetic pole identification. Summary of the invention

[0004] The purpose of the present invention is to provide a method, system, electronic device and medium for detecting the magnetic pole position of a motor, which determines the magnetic pole by injecting a single positive voltage pulse, thereby avoiding the influence of the rotor position movement on the magnetic pole position identification under the double pulse condition, and can determine the magnetic pole position when the motor is rotating, effectively realizing the dynamic magnetic pole identification process, without the need for table lookup, the process is simple, and the detection speed is fast.

[0005] In order to solve the above technical problems, the present invention provides a method for detecting the magnetic pole position of a motor, comprising:

[0006] Determine the current initial position and speed of the rotor in the motor;

[0007] Injecting a positive pulse signal into the motor along the initial position of the rotor, and determining the q-axis current of the motor after the positive pulse signal is injected;

[0008] Determining a correspondence between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed;

[0009] The initial position is corrected based on the corresponding relationship between the initial position and the rotor magnetic pole, and the corrected position value is determined as the magnetic pole position of the rotor in the motor.

[0010] Optionally, determining a current initial position of a rotor in the motor includes:

[0011] Injecting a preset voltage signal having a frequency greater than a preset frequency value into the rotating motor;

[0012] Acquiring a real-time position of a rotor in the motor, and determining the real-time position as a current initial position of the rotor;

[0013] Before injecting a positive pulse signal into the motor along the initial position of the rotor, the method further comprises:

[0014] Stop injecting the preset voltage signal.

[0015] Optionally, determining the q-axis current of the motor after injecting the positive pulse signal includes:

[0016] sampling the motor current of the motor after the positive pulse signal is injected;

[0017] The motor current is subjected to Park transformation using the initial position as a transformation angle to obtain a q-axis current of the motor.

[0018] Optionally, before determining the current initial position of the rotor in the motor, the method further includes:

[0019] Determine whether the current speed of the motor is less than the preset speed value;

[0020] If so, jump to the step of determining the current initial position and speed of the rotor in the motor.

[0021] Optionally, injecting a positive pulse signal into the motor along the initial position of the rotor includes:

[0022] Constructing a dq coordinate system corresponding to the initial position of the rotor;

[0023] A positive pulse signal is injected along the d-axis direction or the -d-axis direction of the dq coordinate system.

[0024] Optionally, determining a correspondence between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed includes:

[0025] Calculating the product of the q-axis current and the rotational speed;

[0026] If the product is greater than zero, the initial position of the rotor coincides with the S pole of the rotor magnetic pole;

[0027] If the product is not greater than zero, the initial position of the rotor coincides with the N pole of the rotor magnetic pole.

[0028] Optionally, correcting the initial position based on a correspondence between the initial position and the rotor magnetic pole, and determining the corrected position value as the magnetic pole position of the rotor in the motor, includes:

[0029] If the initial position of the rotor coincides with the S pole of the rotor magnetic pole, the opposite vector of the initial position is determined as the magnetic pole position of the rotor in the motor;

[0030] If the initial position of the rotor coincides with the N pole of the rotor magnetic pole, the initial position is directly determined as the magnetic pole position of the rotor in the motor.

[0031] In order to solve the above technical problems, the present invention further provides a motor magnetic pole position detection system, comprising:

[0032] An initial position determination unit, used to determine the current initial position and speed of the rotor in the motor;

[0033] A pulse applying unit, used for injecting a positive pulse signal into the motor along the initial position of the rotor, and determining the q-axis current of the motor after the positive pulse signal is injected;

[0034] a position relationship determining unit, configured to determine a corresponding relationship between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed;

[0035] The magnetic pole position determining unit is used to correct the initial position based on the corresponding relationship between the initial position and the rotor magnetic pole, and determine the corrected position value as the magnetic pole position of the rotor in the motor.

[0036] In order to solve the above technical problems, the present invention further provides an electronic device, comprising:

[0037] Memory for storing computer programs;

[0038] A processor is used to implement the steps of the method for detecting the magnetic pole position of the motor as described above.

[0039] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the motor magnetic pole position detection method as described above are implemented.

[0040] The present invention provides a method for detecting the magnetic pole position of a motor. During the rotation of the motor, the position and speed information of the rotor are first determined in real time, and after the initial position of the rotor is determined, a positive pulse signal is injected along the current position of the rotor. Then, the corresponding relationship between the rotor magnetic pole and the initial position of the rotor is determined according to the q-axis current and the speed of the motor after the positive pulse signal is injected, so that the magnetic pole position of the rotor magnetic pole is determined by correcting the initial position of the rotor. The magnetic pole is judged by injecting a single positive voltage pulse, thereby avoiding the influence of the rotor position movement on the magnetic pole position identification under the double pulse condition, and the magnetic pole position can be determined under the rotation of the motor, and the dynamic magnetic pole identification process is effectively realized without the need for table lookup. The process is simple and the detection speed is fast.

[0041] The present invention also provides a motor magnetic pole position detection system, an electronic device and a computer-readable storage medium, which have the same beneficial effects as the above-mentioned motor magnetic pole position detection method. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A schematic flow chart of a method for detecting the magnetic pole position of a motor provided by the present invention;

[0044] Figure 2 A schematic diagram of the motor rotation direction and current vector direction provided by the present invention;

[0045] Figure 3 A schematic flow chart of another method for detecting the magnetic pole position of a motor provided by the present invention;

[0046] Figure 4 A schematic diagram of the waveform of a signal in a motor when a positive pulse signal is injected along the d-axis provided by the first embodiment of the present invention;

[0047] Figure 5 A schematic diagram of the waveform of a signal in a motor when a positive pulse signal is injected along the d-axis provided by the second embodiment of the present invention;

[0048] Figure 6 A schematic diagram of the waveform of a signal in a motor when a positive pulse signal is injected along the d-axis provided by the third embodiment of the present invention;

[0049] Figure 7 A schematic diagram of a waveform of a signal in a motor when a positive pulse signal is injected along the d-axis provided by the fourth embodiment of the present invention;

[0050] Figure 8 A schematic diagram of the waveform of a signal in a motor when a positive pulse signal is injected along the -d axis provided by the first embodiment of the present invention;

[0051] Fig. 9 A schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the -d axis provided by the second embodiment of the present invention;

[0052] Fig.10 A schematic diagram of the waveform of a signal in a motor when a positive pulse signal is injected along the -d axis provided by the third embodiment of the present invention;

[0053] Fig.11 A schematic diagram of a waveform of a signal in a motor when a positive pulse signal is injected along the -d axis provided by the fourth embodiment of the present invention;

[0054] Fig.12 A schematic structural diagram of a magnetic pole position detection system for a motor provided by the present invention;

[0055] Fig.13 The present invention provides a schematic structural diagram of an electronic device. DETAILED DESCRIPTION

[0056] The core of the present invention is to provide a method, system, electronic device and medium for detecting the magnetic pole position of a motor. The magnetic pole is judged by injecting a single positive voltage pulse, thereby avoiding the influence of the rotor position movement on the magnetic pole position identification under the double pulse condition. The magnetic pole position can be determined when the motor is rotating, and the dynamic magnetic pole identification process is effectively realized without the need for table lookup. The process is simple and the detection speed is fast.

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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. 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.

[0058] Please refer to Figure 1 , Figure 1 A flow chart of a method for detecting the magnetic pole position of a motor provided by the present invention; please refer to Figure 2 , Figure 2 A schematic diagram of a motor rotation direction and a current vector direction provided by the present invention; To solve the above technical problems, the present invention provides a method for detecting the magnetic pole position of a motor, comprising:

[0059] S11: Determine the current initial position and speed of the rotor in the motor;

[0060] It is not difficult to understand that the magnetic pole position of the motor refers to the magnetic pole position of the rotor in the motor. Therefore, to determine the magnetic pole position of the motor, it is necessary to first determine the real-time position of the rotor during rotation. The real-time position of the rotor may indicate the same or opposite direction as the actual direction indicated by the rotor magnetic field. Therefore, it is necessary to inject a positive pulse signal to identify the actual correspondence between the initial position of the rotor and the rotor magnetic pole. Considering that the rotor speed is required in the subsequent process of determining the magnetic pole position, the current rotor speed is also determined when determining the real-time position of the rotor.

[0061] It should be noted that if Figure 2 As shown, when analyzing the working process of the motor, the dq axis coordinate system (two-phase synchronous rotating coordinate system) and the αβ axis coordinate system (two-phase stationary coordinate system) of the motor are usually established. The β axis leads the α axis by 90 degrees along the rotation direction. The axis where the α phase is located is specified as the reference axis, and the axis where the α phase is located is specified as the zero degree position. The central axis of the rotor magnetic pole N pole is taken as the d axis, and the q axis leads the d axis by 90 degrees along the rotation direction. During the rotation of the motor, the position of the rotor, including the current initial position of the rotor, can be realized in the form of a position angle. The actual position of the rotor is the angle between the d axis and the α axis, and this angle is an electrical angle. The specific method for determining the current initial position of the rotor and the implementation method are not particularly limited in this application.

[0062] S12: injecting a positive pulse signal into the motor along the initial position of the rotor, and determining the q-axis current of the motor after the positive pulse signal is injected;

[0063] It is understandable that during the rotation of the motor, the magnetic pole indicated by the initial position of the rotor may be the N pole or the S pole. Therefore, it is necessary to further determine the correspondence between the initial position of the rotor and the rotor magnetic pole in order to accurately determine the actual position of the rotor magnetic pole. In response to this situation, the present application injects a positive voltage pulse along the initial position of the rotor. After the positive voltage pulse is injected, the motor and the rotor will continue to rotate under the action of the positive voltage pulse signal. By injecting a single pulse to determine the magnetic pole, there is no need to look up a table, the process is simple, and the detection speed is fast. The present application does not make any special restrictions on the voltage size and implementation method of the positive pulse signal.

[0064] S13: determining the correspondence between the initial position of the rotor and the rotor magnetic pole based on the q-axis current and the rotational speed;

[0065] It should be noted that when the initial position of the rotor coincides with different magnetic poles, the directions of the q-axis current and speed of the motor under the action of the positive pulse signal will be significantly different. Taking the rotor position coincident with the N pole of the rotor magnetic pole as an example, after injecting a positive voltage pulse signal, the voltage equation of the motor is: ; Among them, V p is the voltage of the positive pulse signal, p is the differential operator, ω is the synchronous speed of the motor, is the permanent magnet flux of the motor, is the motor winding phase resistance, L d is the d-axis inductance of the motor, L q is the q-axis inductance of the motor, I d is the d-axis current of the motor, I q is the q-axis current of the motor.

[0066] During the positive pulse injection process, due to i q Amplitude relative to i d The derivative ratio of i is small, and the d-axis voltage equation can be ignored. q The cross component of the stator resistance can be ignored considering the small voltage drop of the stator resistance. Therefore, it can be considered that at the end of the injection of the positive pulse, the d-axis current expression is: ;in, is the pulse width of the positive pulse signal. Substituting it into the q-axis equation, we can get the approximate value: .

[0067] It is not difficult to see that is a positive pulse signal, which must be a positive value, and , L q , These values ​​must also be positive, so when the positive pulse signal is injected, when the estimated initial position of the rotor is the same as the N pole of the magnetic pole, the current I q The sign of is opposite to the direction of the rotor speed ω, such as Figure 2 As shown, when the motor rotates forward, the speed ω is defined as positive, and the motor current I s The projection component I on the q axis q In the negative half cycle of the q axis, that is, the q axis current I q is negative; when the motor reverses, the speed ω is defined as negative, and the motor current I s The projection component I on the q axis q In the positive half cycle of the q axis, that is, the q axis current I q Although the above calculation formula for the q-axis current is estimated, in the process of determining the magnetic pole position, only the q-axis current I q The sign of is sufficient, and the amplitude does not affect the final result, so the above assumptions and calculation process are completely reasonable.

[0068] Furthermore, it can be seen from the estimation formula of the q-axis current that the magnitude of the q-axis current is related to the pulse width of the positive pulse signal. Therefore, by increasing the pulse width of the positive pulse signal, the magnitude of the q-axis current in the process of determining the magnetic pole position can be effectively increased, and a larger q-axis current is more conducive to sampling detection. Therefore, increasing the width of the voltage amplitude of the injected positive pulse signal is more effective for I q The effect is more obvious, the q-axis current can be obtained more accurately and conveniently, and the accuracy is higher when judging the positive and negative signs of the q-axis current. Therefore, a preferred embodiment is to select a positive pulse signal with a pulse width greater than a preset value.

[0069] S14: Correcting the initial position based on the corresponding relationship between the initial position and the rotor magnetic pole, and determining the corrected position value as the magnetic pole position of the rotor in the motor.

[0070] It is not difficult to understand that after determining the correspondence between the initial position of the rotor and the rotor magnetic pole, the motor magnetic pole position can be finally determined according to different correspondences. The motor magnetic pole position refers to the position of the N pole in the rotor magnetic pole, which is generally achieved by electrical angle. Therefore, the magnetic pole position can be determined directly according to the initial position of the rotor. The magnetic pole is determined by injecting a single positive voltage pulse without table lookup. The process is simple and the detection speed is fast. At the same time, the method of dynamically detecting the rotor position can realize the dynamic magnetic pole identification process of the rotating motor.

[0071] The present invention provides a method for detecting the magnetic pole position of a motor. During the rotation of the motor, the position and speed information of the rotor are first determined in real time, and after the initial position of the rotor is determined, a positive pulse signal is injected along the current position of the rotor. Then, the corresponding relationship between the rotor magnetic pole and the initial position of the rotor is determined according to the q-axis current and the speed of the motor after the positive pulse signal is injected, so that the magnetic pole position of the rotor magnetic pole is determined by correcting the initial position of the rotor. The magnetic pole is judged by injecting a single positive voltage pulse, thereby avoiding the influence of the rotor position movement on the magnetic pole position identification under the double pulse condition, and the magnetic pole position can be determined under the rotation of the motor, and the dynamic magnetic pole identification process is effectively realized without the need for table lookup. The process is simple and the detection speed is fast.

[0072] Based on the above examples: Figure 3 , Figure 3 A schematic flow chart of another method for detecting the magnetic pole position of a motor provided by the present invention.

[0073] As an optional embodiment, determining a current initial position of a rotor in a motor includes:

[0074] Injecting a preset voltage signal having a frequency greater than a preset frequency value into the rotating motor;

[0075] Obtain the real-time position of the rotor in the motor, and determine the real-time position as the current initial position of the rotor;

[0076] Before injecting a positive pulse signal into the motor along the initial position of the rotor, it also includes:

[0077] Stop injecting the preset voltage signal.

[0078] It is understandable that the process of determining the real-time position of the rotor can be realized by injecting a high-frequency voltage signal. In particular, when the speed of the motor is low, the rotor can be controlled to reach a certain speed by injecting a high-frequency voltage signal. When the back electromotive force of the motor increases with the increase of the rotor speed, the back electromotive force can be used to determine the real-time position of the rotor. At the same time, in order to avoid the subsequent high-frequency voltage signal affecting the process of the positive pulse signal controlling the rotation of the motor, after determining the initial position of the rotor, the injection of the high-frequency voltage signal can be stopped. When injecting a high-frequency voltage signal, it is generally injected along the direct axis in the synchronous rotating coordinate system dq estimated according to the rotor to control the rotation of the rotor. The specific type and implementation method of the preset voltage signal are not particularly limited in this application. Generally, a high-frequency voltage signal with a frequency not less than 10 times the rated frequency of the motor is used to implement the preset voltage signal, which can be implemented specifically by a square wave voltage.

[0079] Specifically, the use of high-frequency voltage signals can effectively increase the back electromotive force of the motor, and then the back electromotive force can be used to extract the position information of the rotor, thereby realizing the process of determining the real-time position of the rotor; the process of determining the initial position and speed of the rotor is not limited to the method provided in this embodiment, and can also be implemented in other ways, and the present application does not make any special limitations here.

[0080] As an optional embodiment, determining the q-axis current of the motor after the positive pulse signal is injected includes:

[0081] sampling the motor current of the motor after the positive pulse signal is injected;

[0082] The motor current is subjected to Park transformation using the initial position as the transformation angle to obtain the q-axis current of the motor.

[0083] It is not difficult to understand that the q-axis current can be realized by performing a Park transformation on the motor current. The Park transformation can project the a, b, and c three-phase currents of the stator onto the direct axis (d-axis) that rotates with the rotor, the quadrature axis (q-axis), and the zero axis (0-axis) that is perpendicular to the dq plane. In the process of Park transformation, the initial position of the rotor is also required to determine the coordinate system positions of the d-axis and q-axis. Therefore, the initial position of the rotor is required to be used as the transformation angle so that the Park transformation can accurately project the motor current onto the q-axis, thereby obtaining the q-axis current of the motor. The specific implementation method of the Park transformation is not particularly limited in this application, and the q-axis current can also be determined by other coordinate transformation methods. There are many options for sampling the motor current, which can be implemented by setting a current sensor, etc. This application does not make any special restrictions here.

[0084] Specifically, the motor current can be directly converted into the q-axis current by using the Park transformation, and the q-axis current can be directly acquired by means of coordinate transformation projection, which is simple, effective, and easy to implement, and can ensure the accuracy and reliability of the acquired q-axis current.

[0085] As an optional embodiment, before determining the current initial position of the rotor in the motor, the method further includes:

[0086] Determine whether the current speed of the motor is less than the preset speed value;

[0087] If so, jump to the step of determining the current initial position and speed of the rotor in the motor.

[0088] It can be understood that when the motor is rotating at a low speed, the control effect of the positive pulse signal on the motor is more obvious, and the voltage equation of the motor under the action of the positive pulse signal will completely follow the voltage equation in the above derivation process. Therefore, when the motor rotor is running at a low speed, the motor magnetic pole position detection method provided in this application has the highest accuracy, and the low-speed running time period can be selected during the operation of the motor to determine the motor's magnetic pole position; low speed refers to a speed not exceeding 10% of the rated speed of the motor, so the preset speed value can be set and adjusted according to the specific situation of the rated speed of the motor, and this application does not make any special limitations here.

[0089] Specifically, the present invention provides a method for detecting the magnetic pole position of a motor rotating at a low speed. After injecting a square wave voltage under the estimated rotating coordinates to obtain the dynamic rotor position, the magnetic pole is judged by injecting a single positive voltage pulse. There is no need to look up a table, the process is simple, and the detection speed is fast. Especially when the motor is running at a low speed, the accuracy of the entire detection method is relatively high.

[0090] As an optional embodiment, injecting a positive pulse signal into the motor along the initial position of the rotor includes:

[0091] Construct a dq coordinate system corresponding to the initial position of the rotor;

[0092] A positive pulse signal is injected along the d-axis direction or -d-axis direction of the dq coordinate system.

[0093] It is not difficult to understand that in order to realize the control of the rotor rotation by the positive pulse signal, when injecting the positive pulse signal, it is necessary to inject along the direct axis in the estimated synchronous rotating coordinate system dq. The synchronous rotating coordinate system dq refers to a synchronous rotating coordinate system including the d-axis and the q-axis constructed according to the position of the rotor. The positive pulse signal can be injected along the d-axis direction or along the -d-axis direction, and both can realize the control of the rotor. In comparison, injection along the d-axis direction can generate a larger motor current, thereby improving the accuracy and reliability of subsequent sampling of the motor current.

[0094] Specifically, considering that the synchronous rotating coordinate system itself is constructed and estimated based on the real-time position of the rotor, by directly injecting a positive pulse signal along the direct axis direction, the input voltage can be effectively and directly applied to the rotor itself, thereby realizing vector control based on rotor magnetic field orientation.

[0095] As an optional embodiment, determining the correspondence between the initial position of the rotor and the rotor magnetic pole based on the q-axis current and the rotational speed includes:

[0096] Calculate the product of the q-axis current and the speed;

[0097] If the product is greater than zero, the initial position of the rotor coincides with the S pole of the rotor magnetic pole;

[0098] If the product is not greater than zero, the initial position of the rotor coincides with the N pole of the rotor magnetic pole.

[0099] It can be understood that by calculating the estimation formula of the q-axis current, it can be obtained that when the rotor position coincides with the N pole of the rotor magnetic pole, the current I q The sign of is opposite to the direction of the rotor speed ω; similarly, it can be inferred that when the rotor position coincides with the S pole of the rotor magnetic pole, the current I q The sign of is the same as the direction of the rotor speed ω; based on this, the corresponding relationship between the rotor position and the rotor magnetic pole can be determined according to the positive or negative situation of the product of the q-axis current and the speed, that is, which pole of the rotor magnetic pole coincides with the current initial position of the rotor.

[0100] Please note that, please refer to Figure 4 , Figure 4 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the d-axis provided by the present invention; please refer to Figure 5 , Figure 5This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the d-axis provided by the present invention; please refer to Figure 6 , Figure 6 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the d-axis provided by the present invention; please refer to Figure 7 , Figure 7 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the d-axis provided by the present invention; please refer to Figure 8 , Figure 8 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the -d axis provided by the present invention; please refer to Fig. 9 , Fig. 9 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the -d axis provided by the present invention; please refer to Fig.10 , Fig.10 This is a schematic diagram of the waveform of the signal in the motor when a positive pulse signal is injected along the -d axis provided by the present invention; please refer to Fig.11 , Fig.11 The fourth waveform diagram of the signal in the motor when a positive pulse signal is injected along the -d axis provided by the present invention; this judgment basis can be demonstrated by taking a permanent magnet motor with a known magnetic pole position as an example, and the motor parameters of the permanent magnet motor include: 0.4Wb, 0.6Ω, L d 12mH, L q The motor has a current of 20mH, a pole pair number of 2, and an initial electrical angular velocity of 16rad / s. Figure 4-Figure 7 To assume that the initial position The0 has been acquired, only the current waveform of the positive pulse voltage excitation injected along the d-axis is shown. Figure 8-Figure 11 Assuming that the initial position The0 has been obtained, only the current waveform of the positive pulse voltage excitation injected along the d-axis is shown. The horizontal axis of these waveform diagrams is time, and the unit is second (s). Each waveform diagram includes four parts. The first part is a waveform diagram of the d-axis current and q-axis current of the motor changing with time under the action of the positive pulse signal. The second part is a waveform diagram of the angular frequency of the motor changing with time under the action of the positive pulse signal. The third part is a waveform diagram of the injected positive pulse signal. The fourth part is a waveform diagram of the estimated rotor position, that is, the initial position of the rotor The0 and the rotor pole position changing with time under the action of the positive pulse signal. Among them, Figure 4 It is the current response when the rotor position converges to the N pole when the motor rotates forward, that is, when the motor rotates forward, it is obvious that the criterion m_F=ω*Iq<0; Figure 5 The current response when the rotor position converges to the S pole at the positive speed, obviously, the criterion m_F=ω*Iq>0; Figure 6The current response when the rotor position converges to the N pole value at a negative speed. Obviously, the criterion m_F=ω*Iq<0; Figure 7 The current response when the rotor position converges to the S pole at a negative speed. Obviously, the criterion m_F=ω*Iq>0; Figure 8 The current response when the rotor position converges to the N pole is positive speed. Obviously, the criterion m_F=ω*Iq<0; Fig. 9 The current response when the rotor position converges to the S pole at the positive speed, obviously, the criterion m_F=ω*Iq>0; Fig.10 The current response when the rotor position converges to the N pole value at a negative speed. Obviously, the criterion m_F=ω*Iq<0; Fig.11 The current response when the rotor position converges to the S pole at a negative speed, obviously, the criterion m_F=ω*Iq>0. It is not difficult to find that injecting a positive pulse signal along the -d axis is also injecting a negative pulse signal along the d axis, and whether injecting a positive pulse signal along the d axis or injecting a positive pulse signal along the -d axis will not change the way of determining the rotor magnetic pole position according to the sign of the q-axis current and the direction of the speed. Therefore, the corresponding relationship between the rotor position and the rotor magnetic pole can be directly determined according to the positive and negative situation of the product of the q-axis current and the speed.

[0101] Specifically, it is not difficult to find from the estimation formula of the q-axis current that when the rotor position coincides with different rotor magnetic poles, the positive and negative signs of the q-axis current will change accordingly, and when the rotor position coincides with the N pole, the signs of the q-axis current and the rotational speed must be opposite, and when the rotor position coincides with the S pole, the signs of the q-axis current and the rotational speed must be the same. The method of directly using the product of the q-axis current and the rotational speed to determine the corresponding relationship between the rotor position and the rotor magnetic pole is simple, effective, and easy to implement.

[0102] As an optional embodiment, the initial position is corrected based on the corresponding relationship between the initial position and the rotor magnetic pole, and the corrected position value is determined as the magnetic pole position of the rotor in the motor, including:

[0103] If the initial position of the rotor coincides with the S pole of the rotor magnetic pole, the opposite vector of the initial position is determined as the magnetic pole position of the rotor in the motor;

[0104] If the initial position of the rotor coincides with the N pole of the rotor magnetic pole, the initial position is directly determined as the magnetic pole position of the rotor in the motor.

[0105] It is not difficult to understand that if the initial position of the rotor coincides with the S pole of the rotor magnetic pole, it means that the determined initial position of the rotor is exactly opposite to the magnetic pole position of the rotor. At this time, the initial position needs to be The0+π, so that the opposite angle corresponding to the initial position is determined as the magnetic pole position of the rotor; if the initial position of the rotor coincides with the N pole of the rotor magnetic pole, the initial position can be directly determined as the magnetic pole position of the rotor in the motor.

[0106] As a specific embodiment, Figure 3 As shown, determining the magnetic pole position of the motor mainly includes the following steps.

[0107] Step 1: Inject a high-frequency voltage signal into the low-speed rotating motor to dynamically obtain the real-time position The0 and speed ω of the rotor;

[0108] Step 2: Stop injecting the high-frequency signal and inject a positive voltage pulse V in the direction of the initial position The0 of the rotor obtained in step 1. p , where the positive voltage pulse V p The pulse width is T p ;

[0109] Step 3: Sample the motor current and calculate the current I according to the rotor position The0 in step 1 q ;

[0110] Step 4: According to the sign of the speed ω and the current I in step 1 q The sign determines the magnetic pole position. Let m_F equal the product of the speed ω and the current Iq, that is, m_F=ω*I q When m_F>0, it means that the initial position observation result of the rotor coincides with the S pole of the rotor, and the magnetic pole position The is equal to The0+π; when m_F<0, it means that the initial position observation result coincides with the N pole of the rotor, and the identified magnetic pole position The is equal to The0.

[0111] Specifically, after determining which pole of the rotor magnetic pole the rotor position corresponds to based on the product of the rotational speed ω and the current Iq, the magnetic pole position can be directly determined based on the overlap between the two. The rotor position will directly overlap with the magnetic pole position or be completely opposite, and the rotor position is realized in the form of electrical angles. Therefore, the magnetic pole position that is completely opposite to the rotor position can be directly determined by increasing 180°.

[0112] Please refer to Fig.12 , Fig.12 The present invention provides a schematic diagram of the structure of a motor magnetic pole position detection system; To solve the above technical problems, the present invention also provides a motor magnetic pole position detection system, including:

[0113] An initial position determination unit 11, used to determine the current initial position and speed of the rotor in the motor;

[0114] A pulse applying unit 12, used to inject a positive pulse signal into the motor along the initial position of the rotor, and determine the q-axis current of the motor after the positive pulse signal is injected;

[0115] A position relationship determination unit 13, used to determine the corresponding relationship between the initial position of the rotor and the rotor magnetic pole based on the q-axis current and the rotation speed;

[0116] The magnetic pole position determination unit 14 is used to correct the initial position based on the corresponding relationship between the initial position and the rotor magnetic pole, and determine the corrected position value as the magnetic pole position of the rotor in the motor.

[0117] As an optional embodiment, the initial position determining unit 11 includes:

[0118] A high-frequency signal injection unit, used for injecting a preset voltage signal having a frequency greater than a preset frequency value into the rotating motor;

[0119] An initial position determination subunit, used to obtain the real-time position of the rotor in the motor, and determine the real-time position as the current initial position of the rotor;

[0120] Also includes:

[0121] The injection stop unit is used to stop injecting the preset voltage signal.

[0122] As an optional embodiment, the pulse applying unit 12 includes:

[0123] A current sampling unit, used for sampling the motor current of the motor after the positive pulse signal is injected;

[0124] The q-axis current determining unit is used to perform a Park transformation on the motor current by taking the initial position as a transformation angle to obtain the q-axis current of the motor.

[0125] As an optional embodiment, it also includes:

[0126] The rotation speed determination unit is used to determine whether the current rotation speed of the motor is less than a preset rotation speed value; if so, the initial position determination unit 11 is triggered.

[0127] As an optional embodiment, the pulse applying unit 12 includes:

[0128] A coordinate construction unit, used for constructing a dq coordinate system corresponding to the initial position of the rotor;

[0129] The pulse applying subunit is used to inject a positive pulse signal along the d-axis direction or the -d-axis direction of the dq coordinate system.

[0130] As an optional embodiment, the position relationship determining unit 13 includes:

[0131] A calculation unit, used for calculating the product of the q-axis current and the rotational speed;

[0132] a first relationship determination unit, configured to determine that if the product is greater than zero, the initial position of the rotor coincides with the S pole of the rotor magnetic pole;

[0133] The second relationship determining unit is used for determining that if the product is not greater than zero, the initial position of the rotor coincides with the N pole of the rotor magnetic pole.

[0134] As an optional embodiment, the magnetic pole position determining unit 14 includes:

[0135] a first position determining unit, configured to determine the opposite vector of the initial position as the magnetic pole position of the rotor in the motor if the initial position of the rotor coincides with the S pole of the rotor magnetic pole;

[0136] The second position determining unit is used to directly determine the initial position as the magnetic pole position of the rotor in the motor if the initial position of the rotor coincides with the N pole of the rotor magnetic pole.

[0137] For an introduction to a motor magnetic pole position detection system provided by the present invention, please refer to the embodiment of the motor magnetic pole position detection method described above, and the present invention will not be described in detail here.

[0138] Please refer to Fig.13 , Fig.13 The present invention provides a schematic diagram of the structure of an electronic device. To solve the above technical problems, the present invention also provides an electronic device, including:

[0139] A memory 21, used for storing computer programs;

[0140] The processor 22 is used to implement the steps of the aforementioned method for detecting the magnetic pole position of the motor.

[0141] Among them, the processor 22 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 22 can be implemented in at least one hardware form of DSP (Digital Signal Processor), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 22 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit; the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 22 may integrate a GPU (graphics processing unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 22 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0142] The memory 21 may include one or more computer-readable storage media, which may be non-transitory. The memory 21 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 21 is at least used to store the following computer program, wherein, after the computer program is loaded and executed by the processor 22, the relevant steps of the method for detecting the magnetic pole position of the motor disclosed in any of the aforementioned embodiments can be implemented. In addition, the resources stored in the memory 21 may also include an operating system and data, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system may include Windows, Unix, Linux, etc. The data may include, but is not limited to, data of the method for detecting the magnetic pole position of the motor, etc.

[0143] In some embodiments, the electronic device may further include a display screen, an input and output interface, a communication interface, a power supply, and a communication bus.

[0144] It can be understood by those skilled in the art that Fig.13 The structure shown in the figure does not constitute a limitation on the electronic device, and may include more or fewer components than shown in the figure.

[0145] For an introduction to an electronic device provided by the present invention, please refer to the embodiment of the magnetic pole position detection method of the above-mentioned motor, and the present invention will not be described in detail here.

[0146] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the motor magnetic pole position detection method as described above are implemented.

[0147] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. Specifically, the computer-readable storage medium may include but is not limited to any type of disk, including a floppy disk, an optical disk, and a mobile hard disk, or any type of medium or device suitable for storing instructions, data, etc., and the present application does not make any special restrictions here.

[0148] For an introduction to a computer-readable storage medium provided by the present invention, please refer to the embodiment of the above-mentioned method for detecting the magnetic pole position of a motor, and the present invention will not be described in detail here.

[0149] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0150] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0151] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0152] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting the magnetic pole position of a motor, characterized in that: include: Determine the current initial position and speed of the rotor in the motor; Injecting a positive pulse signal into the motor along the initial position of the rotor, and determining the q-axis current of the motor after the positive pulse signal is injected; Determining a correspondence between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed; The initial position is corrected based on the corresponding relationship between the initial position and the rotor magnetic pole, and the corrected position value is determined as the magnetic pole position of the rotor in the motor.

2. The method for detecting the magnetic pole position of a motor according to claim 1, characterized in that: Determine the current initial position of the rotor in the motor, including: Injecting a preset voltage signal having a frequency greater than a preset frequency value into the rotating motor; Acquiring a real-time position of a rotor in the motor, and determining the real-time position as a current initial position of the rotor; Before injecting a positive pulse signal into the motor along the initial position of the rotor, the method further comprises: Stop injecting the preset voltage signal.

3. The method for detecting the magnetic pole position of a motor according to claim 1, characterized in that: Determining the q-axis current of the motor after injecting the positive pulse signal comprises: sampling the motor current of the motor after the positive pulse signal is injected; The motor current is subjected to Park transformation using the initial position as a transformation angle to obtain a q-axis current of the motor.

4. The method for detecting the magnetic pole position of a motor according to claim 1, characterized in that: Before determining the current initial position of the rotor in the motor, it also includes: Determine whether the current speed of the motor is less than the preset speed value; If so, jump to the step of determining the current initial position and speed of the rotor in the motor.

5. The method for detecting the magnetic pole position of a motor according to any one of claims 1 to 4, characterized in that: Injecting a positive pulse signal into the motor along the initial position of the rotor, comprising: Constructing a dq coordinate system corresponding to the initial position of the rotor; A positive pulse signal is injected along the d-axis direction or the -d-axis direction of the dq coordinate system.

6. The method for detecting the magnetic pole position of a motor according to claim 5, characterized in that: Determining a correspondence between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed includes: Calculating the product of the q-axis current and the rotational speed; If the product is greater than zero, the initial position of the rotor coincides with the S pole of the rotor magnetic pole; If the product is not greater than zero, the initial position of the rotor coincides with the N pole of the rotor magnetic pole.

7. The method for detecting the magnetic pole position of a motor according to claim 6, characterized in that: The initial position is corrected based on the corresponding relationship between the initial position and the rotor magnetic pole, and the corrected position value is determined as the magnetic pole position of the rotor in the motor, including: If the initial position of the rotor coincides with the S pole of the rotor magnetic pole, the opposite vector of the initial position is determined as the magnetic pole position of the rotor in the motor; If the initial position of the rotor coincides with the N pole of the rotor magnetic pole, the initial position is directly determined as the magnetic pole position of the rotor in the motor.

8. A magnetic pole position detection system for a motor, characterized in that: include: An initial position determination unit, used to determine the current initial position and speed of the rotor in the motor; A pulse applying unit, used for injecting a positive pulse signal into the motor along the initial position of the rotor, and determining the q-axis current of the motor after the positive pulse signal is injected; a position relationship determining unit, configured to determine a corresponding relationship between an initial position of the rotor and a rotor magnetic pole based on the q-axis current and the rotational speed; The magnetic pole position determining unit is used to correct the initial position based on the corresponding relationship between the initial position and the rotor magnetic pole, and determine the corrected position value as the magnetic pole position of the rotor in the motor.

9. An electronic device, characterized in that: include: Memory for storing computer programs; A processor, used to implement the steps of the method for detecting the magnetic pole position of a motor as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for detecting the magnetic pole position of a motor according to any one of claims 1 to 7 are implemented.

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