Rotor position calibration method and device and storage medium
Patent Information
- Application Number
- DE112022007978
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-11-01
- Publication Date
- 2025-09-11
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Area
[0001] The present application relates to the technical field of permanent magnet synchronous motors and, in particular, to a rotor position calibration method, a rotor position calibration device and a storage medium. background
[0002] A permanent magnet synchronous motor is an AC motor. It uses permanent magnets for excitation and therefore has a simple structure, which reduces manufacturing and assembly costs and improves the operational reliability of the motor. Since it requires no excitation current and has no excitation losses, the efficiency and power density of the motor can be increased, making it widely used in various fields.
[0003] During effective operation of a permanent magnet synchronous motor, it is necessary to obtain an accurate, real-time rotor position signal to ensure stable AC output from the motor. The rotor position signal is typically detected by a sensor. If the motor components are not installed correctly or have aged with use, the rotor position signal becomes nonlinear, causing further fluctuations in motor torque and severely affecting normal product use. The existing technical solution involves compensation and calibration on a test bench for the permanent magnet synchronous motor to correct the nonlinear effect during offline motor operation. This solution relies on test bench resources and requires a high-accuracy position signal sensor on the test bench.Therefore, in the conventional technology, the effectiveness of rotor position compensation and calibration depends on the performance of the test bench and the calibration scenarios are fixed, which is not suitable for the permanent magnet synchronous motor in actual application scenarios. Brief description
[0004] According to the present application, a rotor position calibration method, a rotor position calibration device, and a storage medium are provided to solve the technical problem of conventional technology, namely that a rotor position signal of a permanent magnet synchronous motor may be nonlinear during operation, resulting in fluctuations in motor torque. Accordingly, a rotor position can be calibrated to obtain an accurate rotor position signal in real time.
[0005] According to one aspect of the present application, a rotor position calibration method is provided that is applied to a permanent magnet synchronous motor. The method includes: Determining a theoretical position of a target point on a rotor of the motor in accordance with the target speed at each of the periodic times according to a preset target speed; Determining a target driving force according to the target speed, applying the target driving force to the rotor to rotate the rotor, and monitoring an actual position of the target point at each of the periodic time points in real time; determining position errors at multiple time points in a preset measurement period according to the theoretical positions and the actual positions; and Determining an error curve based on the position errors and calibrating a rotor position based on the error curve.
[0006] Furthermore, determining the theoretical position of the target point on the rotor of the motor in accordance with the target speed at each of the periodic times according to the preset target speed includes: Obtaining a theoretical rotation angle of the rotor according to an operation time of the target point and the target rotation speed, and obtaining the theoretical position according to the theoretical rotation angle and an initial position of the rotor.
[0007] Further, determining the target driving force according to the target speed includes: determining the target driving force based on a field-oriented control method and the theoretical position in accordance with the target speed.
[0008] Furthermore, determining the target driving force based on a field-oriented control method and the theoretical position in accordance with the target speed includes: Obtaining a current motor current of the motor, determining a duty cycle of the motor according to the motor current and the theoretical position, and determining the target driving force based on the duty cycle.
[0009] Furthermore, monitoring the actual position of the target point at each of the periodic times in real time includes: Monitoring the actual position of the target point at each of the periodic times by a magnetoelectric position sensor.
[0010] Furthermore, determining the position errors at the plurality of times in a preset measurement period according to the theoretical positions and the actual positions includes: Determining the number of rotation periods of the rotor in the preset measurement period and sampling sequences for sampling the position errors in one of the rotation periods, the sampling sequences being in accordance with the respective periodic times; and
[0011] Determining position errors at multiple times within this rotation period for each of the rotation periods in the preset measurement period based on the sampling sequences, the theoretical positions, and the actual positions. Furthermore, determining the error curve based on the position errors includes calculating an average position error for each of the sampling sequences and determining the error curve based on the average position errors.
[0012] Furthermore, the calibration of the rotor position based on the error curve includes: Determining a current actual position of the target point, determining a current position error in accordance with the current actual position based on the error curve, and calibrating the rotor position based on a linear interpolation method and the current position error.
[0013] Furthermore, the calibration of the rotor position based on the linear interpolation method and the current position error includes: Summing the current actual position and the current position error to obtain a target rotor position of the rotor, and controlling a torque signal of the motor based on the target rotor position to equate the rotor position to the target rotor position.
[0014] Furthermore, before determining the theoretical position of the target point on the rotor of the engine in accordance with the target speed at each of the periodic times according to the preset target speed, the method further includes: obtaining performance information of the engine, determining whether the engine is in an idle state according to the performance information, and calibrating the rotor position in case that the engine is determined to be in an idle state.
[0015] According to another aspect of the present application, a rotor position calibration device is further provided, which is applied to a permanent magnet synchronous motor. The device includes: a theoretical position determination module for determining a theoretical position of a target point on a rotor of the motor in accordance with the target speed at each of the periodic times according to a preset target speed; a drive module and an actual position monitoring module, wherein the drive module is for determining a target driving force according to the target rotational speed and applying the target driving force to the rotor to rotate the rotor, and the actual position monitoring module is for monitoring an actual position of the target point at each of the periodic times in real time; a position error determination module for determining position errors at multiple time points in a preset measurement period according to the theoretical positions and the actual positions; and a rotor position calibration module for determining an error curve based on the position errors and calibrating a rotor position based on the error curve.
[0016] According to another aspect of the present application, a storage medium according to the present application is further provided. A plurality of instructions are stored in the storage medium, and the instructions are configured to be loadable by a processor to execute the rotor position calibration method according to one of the above solutions.
[0017] By one or more of the above-described embodiments of the present application, at least the following technical effects can be achieved.
[0018] In the technical solutions disclosed in the present application, the theoretical positions and the actual positions of the rotor are determined, and the position errors at multiple time points are further calculated. Subsequently, the error curve is determined based on the position errors, and finally, the rotor position is calibrated based on the error curve. The technical solutions of the present application make it possible to calibrate a nonlinear rotor position and obtain an accurate rotor position signal in real time, thus avoiding the problem of motor torque fluctuation. Furthermore, the technical solutions of the present application do not rely on test bench resources and do not impose any requirements on the rotor calibration scenarios. Even if the permanent magnet synchronous motor is installed on the application device, the rotor position can still be calibrated.Therefore, through the technical solutions of the present application, it is possible to obtain an accurate rotor position signal in real time, and these technical solutions can be widely used in permanent magnet synchronous motors in various scenarios. Brief description of the drawings
[0019] Specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings so that the technical solutions and other advantageous effects of the present application will become clear. Fig. 1 is a flowchart showing the steps of a rotor position calibration method according to an embodiment of the present application; Fig. 2 is a schematic diagram showing that a rotor position is nonlinear according to the present application; Fig. 3 is a schematic diagram showing a variation of the rotor position according to the present application; Fig. 4 is another schematic diagram showing that the rotor position is non-linear according to the present application; Fig. 5 is a schematic diagram showing position errors in a rotation period according to the present application; and Fig. 6 is a schematic structural diagram of a rotor position calibration device according to an embodiment of the present application. Detailed description of the embodiments
[0020] Technical solutions according to the embodiments of the present application are described below clearly and completely in conjunction with the accompanying drawings of the embodiments of the present application. It is obvious that the described embodiments represent only a portion of the embodiments of the present application and not all embodiments. Starting from the embodiments of the present application, all other embodiments that a person skilled in the art can derive without creative effort are considered to be within the scope of the present application.
[0021] According to one aspect of the present application, a rotor position calibration method is provided. Fig. Figure 1 is a flowchart illustrating the steps of a rotor position calibration method according to an embodiment of the present application. The rotor position calibration method includes the following steps.
[0022] In step 101, a theoretical position of a target point on a rotor of the motor is determined in accordance with the target speed at each of the periodic timings according to a preset target speed.
[0023] In step 102, a target driving force is determined according to the target rotational speed, the target driving force is applied to the rotor to rotate the rotor, and an actual position of the target point at each of the periodic time points is monitored in real time.
[0024] In step 103, position errors are determined at multiple times in a preset measurement period according to the theoretical positions and the actual positions.
[0025] In step 104, an error curve is determined based on the position errors and a rotor position is calibrated based on the error curve.
[0026] The permanent magnet synchronous motor is an AC motor that mainly consists of a stator, a rotor, an end cap and other components.
[0027] The rotor is a permanent magnet, and its rotational speed is the same as the rotational speed of the stator's rotating magnetic field. If the motor components are not installed correctly or have aged with use, the rotor position signal becomes nonlinear, causing further fluctuations in motor torque and severely affecting normal use of the product. Fig. Figure 2 is a schematic diagram showing that a rotor position is nonlinear according to the present application. Normally, the actual real-time position of the rotor should match the theoretical position. However, improper installation or aging of the motor can cause nonlinearity. When the motor is operating, the rotor is in the actual position in Fig. 2, and there is a position deviation between the theoretical position and the actual position.
[0028] With this solution, the rotor position error can be corrected without relying on a test bench. A necessary condition is that the motor is maintained in a stable state with a self-compensating speed. The prerequisite for eliminating the rotor position error is to allow the motor to rotate at the target speed based on the theoretical rotor position. Only when the motor rotates stably at the target speed can the error be eliminated.
[0029] The following example illustrates how the engine can be kept in a stable state. Fig. Figure 3 is a schematic diagram showing a variation of the rotor position according to the present application. It is assumed that the motor resistance force is 1 Nm and the motor driving force is 5 Nm. When the motor driving force is greater than the motor resistance, the rotor accelerates. As shown in Fig. As shown in Figure 3, it is assumed that a given virtual speed is 20 rpm and a theoretical position signal θ2 of a certain frequency is generated. The actual position θ1 of the rotor gradually approaches the theoretical position during the acceleration process (at a speed not exceeding 20 rpm). If the actual speed exceeds the set 20 rpm, as shown in Fig. As shown in Figure 3, the actual position θ1 exceeds the theoretical position θ2. An angle θe between the actual position θ1 and the theoretical position θ2 can be regarded as a power angle, and a motor torque, a motor current, and the power angle satisfy the following relationship: Tq=Iq*COS(θe), where Tq represents the motor torque, Iq represents the motor current, and θe represents the power angle.
[0030] From the relationship between motor torque, motor current, and power angle, it can be seen that the magnitude of the torque depends on the actual motor current. The accuracy of the motor current depends on the accuracy of the rotor position. The more accurate the rotor position, the closer the actual motor current is to the target current. It can be seen that if the theoretical position θ2 of the rotor is taken as a reference, the accuracy of the motor current and rotor position decreases when the rotor position deviates from the theoretical position θ2. The position accuracy can be represented by COS(θe).
[0031] During the Fig. 3, when the actual position θ1 exceeds the theoretical position θ2, an increase in the power angle θe will cause a decrease in the motor torque Tq. Accordingly, the rotor speed decreases, causing the actual position θ1 to slow down. As the actual position θ1 gradually approaches the theoretical position θ2, the power angle θe decreases. The larger the deviation in rotor position accuracy, the smaller the COS(θe) and the smaller the generated torque. Due to the reduced torque, the speed of the actual rotor position decreases.
[0032] As the power angle θe decreases, the motor torque Tq increases, the motor rotor accelerates, and the acceleration causes the actual position θ1 to gradually deviate from the theoretical position θ2. Accordingly, the power angle θe increases.
[0033] By repeatedly controlling the above two operations, the deviation between the actual position θ1 and the theoretical position θ2 is reduced until the power angle θe is zero.
[0034] In the present application, the rotor position must be calibrated when the engine is in an idle state. For example, calibration-related data is predetermined in the idle state before the engine leaves the factory or in a quasi-idle state generated during engine operation.
[0035] The position error of the motor rotor is primarily caused by the installation positions of the position sensor and the magnet. Therefore, the error value caused by the positions fluctuates less after the device is stowed away. Different rotor speeds only lead to different operating periods of the rotor, but do not cause any significant variation in the error value. Once the rotor calibration data has been determined, the data can be saved and the rotor can be calibrated using the same data within a preset time.
[0036] The above steps 101 to 104 are described in detail below. In step 101, the theoretical position of the target point on the rotor of the motor is determined in accordance with the target speed at each of the periodic timings according to the preset target speed.
[0037] For example, the rotor of a permanent magnet synchronous motor is a permanent magnet. During motor operation, the rotor speed is the same as the rotating magnetic field speed of the stator. Before setting the motor's operating parameters, the target rotor speed is preset based on information such as the required AC current parameters. The motor current is controlled based on the target speed, and the motor torque is further controlled to rotate the rotor. The rotor and stator are provided with a preset starting point, that is, an initial position of the target point. When the rotor rotates stably, the time when the target point passes the initial position is recorded, and a rotor rotation period begins. In each period, the theoretical position of the target point is calculated based on the periodic time point and the target speed.In step 102, the target driving force is determined according to the target rotational speed, the target driving force is applied to the rotor to rotate the rotor, and the actual position of the target point at each of the periodic time points is monitored in real time.
[0038] For example, in a permanent magnet synchronous motor, if the motor current and rotor position are determined, a motor duty cycle can be determined. Internal feedback is formed in the motor about the duty cycle, and the motor current is controlled based on the duty cycle. That is, the target driving force of the motor is controlled to further change the motor torque and make the rotor rotate at the target speed. The motor is equipped with a position sensor for monitoring rotor position information in real time. Various types of position sensors can be used to determine current rotor position information in real time. In the present application, before the position sensor receives the position signal, several periodic timings are preset based on a period duration and an accuracy standard.Each period is divided into a preset number of periods and the rotor position information is collected at a preset time of each period.
[0039] In step 103, the position errors at multiple times in the preset measurement period are determined according to the theoretical positions and the actual positions.
[0040] For example, in the present application, the measurement period is preset. The preset measurement period includes several rotor rotation periods. After the motor is started and the rotor speed is stable, the position errors are calculated at several times in each period according to the calculated theoretical positions and the actual positions monitored in real time.
[0041] In the schematic diagram in Fig. 2, which shows the variation of the rotor position, a periodic position error between the actual position and the theoretical position is ignored. Fig. Figure 4 is another schematic diagram showing that the rotor position is nonlinear according to the present application. More specifically, the schematic diagram of the actual position and the theoretical position is as shown in Fig. 4. The real position error is the sum of the periodic position error and the position error in Fig. 2. In practice, the periodic position error can be Fig. 4 can be easily eliminated. Therefore, the rotor position calibration method according to the present solution is based on the elimination of the periodic position error. Therefore, the position error in the present solution corresponds by default to an error between the actual position and the theoretical position at the same time, as in Fig. 2 shown. Fig. Figure 5 is a schematic diagram showing position errors according to the present application. As shown in Fig. As shown in Figure 5, the variation of the rotor position during a rotation period of the rotor results in a deviation between the actual position and the theoretical position. In the Fig. In the example shown in Figure 5, the rotor's rotation period is divided into 15 parts. Accordingly, 14 position errors result at 14 points in time.
[0042] In step 104, the error curve is determined based on the position errors and the rotor position is calibrated based on the error curve.
[0043] For example, after determining multiple position errors, data processing is performed on the multiple position errors to adjust the error curve. During motor operation, the actual position of the motor rotor is obtained in real time, and the rotor position is calibrated according to the error curve, ensuring precise and stable operation of the permanent magnet synchronous motor.
[0044] Further, the step of determining the theoretical position of the target point on the rotor of the motor in accordance with the target speed at each of the periodic timings according to the preset target speed includes the following steps.
[0045] A theoretical rotation angle of the rotor is determined according to an operation time of the target point and the target speed, and the theoretical position is determined according to the theoretical rotation angle and an initial position of the rotor.
[0046] For example, when the rotor of a permanent magnet synchronous motor is rotating stably, the time at which the target point is at the initial position is determined, and the rotor's operating time is calculated in real time based on the current time and the initial time. Then, based on the operating time and the target speed, the theoretical rotation angle by which the rotor has rotated at the current time is determined. The initial position of the rotor is obtained, the theoretical rotation angle is added to an angle consistent with the initial position, and then the theoretical rotation angle is converted into a center angle to obtain the theoretical position.
[0047] Further, the step of determining the target driving force according to the target rotational speed includes the following step.
[0048] The target driving force is determined based on a field-oriented control method and the theoretical position in accordance with the target speed. Furthermore, the step of determining the target driving force based on a field-oriented control method and the theoretical position in accordance with the target speed includes the following steps.
[0049] A current motor current of the motor is obtained, a duty cycle of the motor is determined according to the motor current and the theoretical position, and the target driving force is determined based on the duty cycle.
[0050] For example, the motor duty cycle is determined by the field-oriented control (FOC) method and the theoretical position. The motor current is controlled according to the duty cycle to further control the motor torque and make the motor run at a certain speed. The duty cycle refers to the ratio of an on-time to an on-time duration of a pulse signal. For an ideal periodic pulse train (such as a square wave), the duty cycle is the ratio of the duration of a positive pulse to the entire pulse period. The duty cycle refers to the ratio of the time of a high level in a period. The square wave has a duty cycle of 50%. The duty cycle is 0.5, which means the positive level occupies 0.5 periods.
[0051] The field-oriented control (FOC) method is also called vector control. Its principle is to convert the control of a three-phase alternating current into the control of a q-axis current that generates torque and a d-axis current that generates the magnetic field through coordinate transformation, thus achieving independent control of the torque and excitation. The magnetic field is represented in the form of a space vector. It is known that the torque is maximized when the direction of a stator magnetic field is perpendicular to the direction of a rotor magnetic field. Therefore, the motor can be ensured to perform well if the directions of the stator and rotor magnetic fields are always perpendicular to each other. Furthermore, the step of monitoring the actual position of the target point at each of the periodic times in real time includes the following step.
[0052] The actual position of the target point at each of the periodic times is monitored by a magnetoelectric position sensor.
[0053] For example, a permanent magnet synchronous motor is equipped with a sensor for measuring the rotor position. Specifically, the actual position of the target point is periodically monitored by a magnetoelectric position sensor. A magnetoelectric sensor is also called an electric or inductive sensor, and is exclusively suitable for dynamic measurement. The principle of a magnetoelectric sensor is to convert an input motion velocity into an induced output potential in a coil through electromagnetic induction. As a typical passive sensor, a magnetoelectric sensor directly converts the mechanical energy of a measurement object into an electrical signal output and does not require an external power supply for operation. A magnetoelectric position sensor features large output power, simple circuitry, and stable zero position and performance, making it widely used.It should be noted that the sensor type is not limited in practice, and other position sensors can also be used, such as a Hall position sensor and an inductive position sensor. The optimal sensor can be determined depending on the practical requirements.
[0054] Further, the step of determining the position errors at the plurality of time points in a preset measurement period according to the theoretical positions and the actual positions includes the following steps.
[0055] The number of rotor rotation periods in the preset measurement period, as well as the sampling sequences for sampling the position errors in one of the rotation periods, are determined. The sampling sequence corresponds to the respective periodic times.
[0056] Position errors at multiple times in this rotation period are determined for each of the rotation periods in the preset measurement period based on the sampling sequences, the theoretical positions, and the actual positions.
[0057] For example, the preset measurement period includes multiple rotation periods. For example, if the preset measurement period includes 10 rotor rotation periods, rotor position data is collected in the 10 periods to calculate the position errors. To improve the accuracy of rotor position calibration, more rotor rotation periods can be provided, for example, 20 or 50 rotor rotation periods, which can make position calibration more accurate. After determining the number of rotor rotation periods in the preset measurement period, sampling is performed at multiple preset times for each rotation period to calculate the rotor position errors. Fig. Figure 5 is a schematic diagram showing position errors according to the present application. As shown in Fig. As shown in Figure 5, there are 14 sampling sequences in a rotation period, each corresponding to 14 periodic time points. Assume that the preset measurement period includes 10 rotation periods of the rotor, and that there are 14 position errors in each rotation period. In the preset measurement period, 140 position errors occur.
[0058] Furthermore, the step of determining the error curve based on the position errors includes the following steps.
[0059] For each of the sampling sequences, an average position error is calculated and the error curve is determined based on the average position errors.
[0060] For each of the sampling sequences, a target position error corresponding to the sampling sequence is obtained in each rotation period in the preset measurement period, thus obtaining a plurality of target position errors corresponding to this sampling sequence. An average of the plurality of target position errors is calculated to obtain an average position error consistent with this sampling sequence. Specifically, to improve the accuracy of error calibration, after obtaining all the position errors in the preset measurement period for each of the sampling sequences, the target position errors corresponding to this sampling sequence are determined from all the rotation periods. Data processing is applied to the position errors corresponding to each sampling sequence, and the average of the plurality of target position errors is calculated to obtain a plurality of average position errors.For example, if the corresponding preset measurement period includes 10 rotor rotation periods and 14 position errors occur in each rotation period, there will be 140 position errors in the preset measurement period. For each of the 14 sampling sequences, the average of the 10 position errors is calculated according to this sequence to obtain 14 average position errors. After all average position errors are determined, data processing is applied to the average position errors, and the error curve is fitted based on a mathematical optimization algorithm.
[0061] Furthermore, the step of calibrating the rotor position based on the error curve includes the following steps.
[0062] A current actual position of the target point is determined, a current position error corresponding to the current actual position is determined based on the error curve, and the rotor position is calibrated based on a linear interpolation method and the current position error. For example, after determining the error curve, the rotor position can be calibrated based on the error curve. The rotor position can also be calibrated using the position errors at several preset times. In one embodiment, the plurality of average position errors can be directly processed by the linear interpolation method, and the rotor position can be compensated using the average position errors.In one embodiment, at the current time of rotor operation, the current actual position is obtained and the position error is obtained in accordance with the current actual position on the error curve, and then the rotor position is calibrated using the linear interpolation method and the position error.
[0063] The linear interpolation method is an interpolation method in which the interpolation function is a first-order polynomial and the interpolation error at any interpolation node is zero. Compared with other interpolation methods, such as parabolic interpolation, linear interpolation is simple and convenient.
[0064] Furthermore, the step of calibrating the rotor position based on the linear interpolation method and the current position error includes the following steps.
[0065] The current actual position and the current position error are summed to obtain a target rotor position of the rotor, and a torque signal of the motor is controlled based on the target rotor position to equate the rotor position with the target rotor position.
[0066] For example, when controlling the motor speed, two control signals are input. One of the control signals relates to the position the rotor is expected to reach, and the other to the torque. In this application, to equate the rotor position with the target rotor position, the target rotor position of the rotor in its current state is first calculated, and then the motor torque signal is controlled based on the target rotor position. To complete the rotor position calibration, the motor controls the rotor speed according to the torque signal.
[0067] Furthermore, the method includes the following steps before the step of determining the theoretical position of the target point on the rotor of the motor in accordance with the target speed at each of the periodic times according to the preset target speed.
[0068] Power information of the engine is obtained, according to the power information it is determined whether the engine is in an idle state, and the rotor position is calibrated in the case where it is determined that the engine is in an idle state.
[0069] For example, to ensure the accuracy of the measured position errors, it is necessary to ensure that the motor is in an idle state when obtaining the position errors. For example, calibration-related data is predetermined in the idle state before the motor leaves the factory or in a quasi-idle state generated during engine operation.
[0070] By one or more of the above-described embodiments of the present application, at least the following technical effects can be achieved.
[0071] In the technical solutions disclosed in the present application, the theoretical positions and the actual positions of the rotor are determined, and the position errors at multiple time points are further calculated. Subsequently, the error curve is determined based on the position errors, and finally, the rotor position is calibrated based on the error curve. The technical solutions of the present application make it possible to calibrate a nonlinear rotor position and obtain an accurate rotor position signal in real time, thus avoiding the problem of motor torque fluctuation. Furthermore, the technical solutions of the present application do not rely on test bench resources and do not impose any requirements on the rotor calibration scenarios. Even if the permanent magnet synchronous motor is installed on the application device, the rotor position can still be calibrated.Therefore, through the technical solutions of the present application, it is possible to obtain an accurate rotor position signal in real time, and these technical solutions can be widely used in permanent magnet synchronous motors in various scenarios.
[0072] Based on the same inventive concept as the rotor position calibration method according to the embodiments of the present application, according to an embodiment of the present application, a rotor position calibration device is further provided that is applied to a permanent magnet synchronous motor. With reference to Fig. 6 includes the device: a theoretical position determination module 201 for determining a theoretical position of a target point on a rotor of the motor in accordance with the target speed at each of the periodic times according to a preset target speed; a drive module 202 and an actual position monitoring module 203, each for determining a target driving force according to the target rotational speed and applying the target driving force to the rotor to rotate the rotor, and monitoring an actual position of the target point at each of the periodic timings in real time; a position error determination module 204 for determining position errors at multiple times within a preset measurement period according to the theoretical positions and the actual positions; and a rotor position calibration module 205 for determining an error curve based on the position errors and calibrating a rotor position based on the error curve.
[0073] In addition, module 201 is used to determine the theoretical position and also to: Obtaining a theoretical rotation angle of the rotor according to an operation time of the target point and the target rotation speed, and obtaining the theoretical position according to the theoretical rotation angle and an initial position of the rotor.
[0074] In addition, the drive module 202 also serves to: Determining the target driving force based on a field-oriented control method and the theoretical position in accordance with the target speed.
[0075] In addition, the drive module 202 also serves to: Obtaining a current motor current of the motor, determining a duty cycle of the motor according to the motor current and the theoretical position, and determining the target driving force based on the duty cycle.
[0076] In addition, the module 203 is used to monitor the actual position and also to: Monitoring the actual position of the target point at each of the periodic times by a magnetoelectric position sensor.
[0077] In addition, the position error determination module 204 further serves to: determine the number of rotation periods of the rotor in the preset measurement period and sampling sequences for sampling the position errors in one of the rotation periods, the sampling sequences being in accordance with the respective periodic times; and
[0078] Determining position errors at multiple times in this rotation period for each of the rotation periods in the preset measurement period based on the sampling sequences, the theoretical positions, and the actual positions.
[0079] In addition, the rotor position calibration module 205 further serves to: calculate an average position error for each of the sampling sequences and determine the error curve based on the average position errors.
[0080] In addition, the rotor position calibration module 205 also serves to: Obtaining a target position error for each of the sampling sequences in accordance with the sampling sequence in each rotation period in the preset measurement period, so as to obtain a plurality of target position errors in accordance with the sampling sequence; and
[0081] Calculating an average of the plurality of target position errors to obtain an average position error consistent with the sampling sequence.
[0082] In addition, the rotor position calibration module 205 also serves to: Determining a current actual position of the target point, determining a current position error in accordance with the current actual position based on the error curve, and calibrating the rotor position based on a linear interpolation method and the current position error.
[0083] Other aspects and implementation details of the rotor position calibration device are the same or similar to the rotor position calibration method described above and are not repeated herein. According to another aspect of the present application, a storage medium according to the present application is further provided. A plurality of instructions are stored in the storage medium, and the instructions are configured to be loadable by a processor to execute the rotor position calibration method according to one of the above solutions.
[0084] In summary, while the present application is disclosed by the above preferred embodiments, the preferred embodiments should not be construed as limitations of the present application. Numerous variations and modifications are possible for those skilled in the art without departing from the spirit and scope of the present application, and the scope of the present application is based on the scope defined by the claims.
Claims
[1] Rotor position calibration method applied to a permanent magnet synchronous motor, comprising: Determining a theoretical position of a target point on a rotor of the motor in accordance with the target speed at each of the periodic times according to a preset target speed; Determining a target driving force according to the target rotational speed, applying the target driving force to the rotor to rotate the rotor, and monitoring an actual position of the target point at each of the periodic times in real time; Determining position errors at a plurality of times in a preset measurement period according to the theoretical positions and the actual positions; and Determining an error curve based on the position errors and calibrating a rotor position based on the error curve. [2] The method of claim 1, wherein determining the theoretical position of the target point on the rotor of the motor in accordance with the target speed at each of the periodic times according to the preset target speed comprises: Obtaining a theoretical rotation angle of the rotor according to an operation time of the target point and the target rotation speed, and obtaining the theoretical position according to the theoretical rotation angle and an initial position of the rotor. [3] The method of claim 1, wherein determining the target driving force according to the target rotational speed comprises: Determining the target driving force based on a field-oriented control method and the theoretical position in accordance with the target speed. [4] The method of claim 3, wherein determining the target driving force based on the field-oriented control method and the theoretical position in accordance with the target speed comprises: Obtaining a current motor current of the motor, determining a duty cycle of the motor according to the motor current and the theoretical position, and determining the target driving force based on the duty cycle. [5] The method of claim 1, wherein monitoring the actual position of the target point at each of the periodic times in real time comprises: Monitoring the actual position of the target point at each of the periodic times by a magnetoelectric position sensor. [6] The method of claim 1, wherein determining the position errors at the plurality of times in the preset measurement period according to the theoretical positions and the actual positions comprises: Determining the number of rotation periods of the rotor in the preset measurement period and sampling sequences for sampling the position errors in one of the rotation periods, the sampling sequences being in accordance with the respective periodic times; and Determining position errors at a plurality of times in this rotation period for each of the rotation periods in the preset measurement period based on the sampling sequences, the theoretical positions and the actual positions. [7] The method of claim 6, wherein determining the error curve based on the position errors comprises: Calculating an average position error for each of the sampling sequences and determining the error curve based on the average position errors. [8] The method of claim 1, wherein calibrating the rotor position based on the error curve comprises: Determining a current actual position of the target point, determining a current position error in accordance with the current actual position based on the error curve, and calibrating the rotor position based on a linear interpolation method and the current position error. [9] The method of claim 8, wherein calibrating the rotor position based on the linear interpolation method and the current position error comprises: Summing the current actual position and the current position error to obtain a target rotor position of the rotor, and controlling a torque signal of the motor based on the target rotor position to equate the rotor position to the target rotor position. [10] The method according to claim 1, wherein the method further comprises, prior to determining the theoretical position of the target point on the rotor of the motor in accordance with the target speed at each of the periodic times according to the preset target speed: Obtaining performance information of the engine, determining whether the engine is in an idle state according to the performance information, and calibrating the rotor position in the event that the engine is determined to be in an idle state. [11] Rotor position calibration device applied to a permanent magnet synchronous motor, comprising: a theoretical position determination module for determining a theoretical position of a target point on a rotor of the motor in accordance with the target speed at each of the periodic times according to a preset target speed; a drive module for determining a target driving force according to the target rotational speed and applying the target driving force to the rotor to rotate the rotor; an actual position monitoring module for monitoring an actual position of the target point at each of the periodic times in real time; a position error determination module for determining position errors at a plurality of times in a preset measurement period according to the theoretical positions and the actual positions; and a rotor position calibration module for determining an error curve based on the position errors and for calibrating a rotor position based on the error curve. [12] A storage medium storing a plurality of instructions, the instructions being configured to be loaded by a processor to perform the rotor position calibration method of any one of claims 1 to 10.