Method and device for calibrating zero point of rotary transformer

Abstract

The invention provides a rotary transformer zero point calibration method and device, and relates to the technical field of motors, and the calibration method comprises the steps: executing the following control steps for a quadrature axis of a motor: outputting a first control instruction when the motor is in a no-load state, and outputting a first voltage control instruction when the output voltage of a direct axis of the motor is monitored to meet a first condition, after the position of the rotor of the motor is stable, obtaining a first angle value corresponding to the quadrature axis according to a resolver angle value detected by a resolver sensor; executing the following control steps for the direct axis of the motor: outputting a second control instruction, outputting a second voltage control instruction when it is monitored that the output voltage of the quadrature axis of the motor meets a second condition, and obtaining a second angle value corresponding to the direct axis according to a resolver angle value detected by a resolver sensor after the rotor position of the motor is stable; and calibrating the zero point of the rotary transformer according to the first angle value and the second angle value. According to the invention, calibration of the zero point of the rotary transformer is realized.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and more specifically, to a method and device for calibrating a resolver zero point. Background Art

[0002] The resolver position sensor is a key component for obtaining the motor rotor position, and the resolver zero point is the core element of the motor controller calibration. However, the resolver zero point is often inconsistent with the rotor position zero point. Any deviation in the rotor position may cause torque control inaccuracy, decreased stability of the current regulator, and even cause overcurrent damage to the drive. Existing technologies mostly rely on advanced algorithms or high braking torque conditions for precise calibration, which places strict requirements on the control algorithm and calibration environment. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a method and device for calibrating the zero point of a resolver. Through the present application, rapid and accurate calibration of the zero point of the resolver can be achieved, thereby improving the calibration efficiency and calibration accuracy.

[0004] In a first aspect, the present application provides a method for calibrating a resolver zero point, the method comprising: executing the following control steps for the quadrature axis of a motor: when the motor is in a no-load state, outputting a first control instruction, the first control instruction comprising a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct axis current value of the motor; when it is monitored that the output voltage of the direct axis of the motor satisfies a first condition, outputting a first voltage control instruction for controlling the quadrature axis voltage value of the motor; after the rotor position of the motor is stable, obtaining a first angle value corresponding to the quadrature axis according to the angle value detected by the resolver sensor; executing the following control steps for the direct axis of the motor: when the motor is in a no-load state, outputting a first control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct axis current value of the motor; when it is detected that the output voltage of the direct axis of the motor satisfies a first condition, outputting a first voltage control instruction for controlling the quadrature axis voltage value of the motor; after the rotor position of the motor is stable, obtaining a first angle value corresponding to the quadrature axis according to the angle value detected by the resolver sensor; executing the following control steps for the direct axis of the motor: The following control steps: when the motor is in a no-load state, output a second control instruction, the second control instruction includes the first rotor control instruction and a second current control instruction for controlling the quadrature-axis current value of the motor; when it is monitored that the output voltage of the quadrature-axis of the motor meets the second condition, output a second voltage control instruction for controlling the direct-axis voltage value of the motor; after the rotor position is stable, obtain a second angle value corresponding to the direct axis according to the angle value detected by the resolver sensor; calibrate the resolver zero point of the resolver sensor according to the first angle value and the second angle value so that the resolver zero point corresponds to the rotor position zero point of the motor.

[0005] In a possible implementation manner, the first rotor control instruction indicates that the rotor angle value is controlled to be zero, the first current control instruction indicates that the direct-axis current value is controlled to be zero, the first condition indicates that the direct-axis voltage output is a voltage value corresponding to the direct-axis current value of zero, the first voltage control instruction indicates that the quadrature-axis voltage is controlled to be increased, and the first angle value includes a first resolver angle value, wherein the first resolver angle value is obtained in the following manner: when the motor is in a no-load state, the first control instruction is output to fix the direct-axis voltage output to a voltage value corresponding to the direct-axis current value of zero; the first voltage control instruction is output to increase the quadrature-axis voltage by controlling the quadrature-axis injection current; when it is monitored that the quadrature-axis current increases to a first specified current value, a third voltage control instruction for stopping the increase of the quadrature-axis voltage is output, and the angle value detected by the resolver sensor within a preset time length is continuously obtained, so as to average all angle values ​​detected within the preset time length to obtain the first resolver angle value; and a fourth voltage control instruction for controlling the quadrature-axis voltage to decrease is output to decrease the quadrature-axis voltage to zero.

[0006] In a possible implementation, the first angle value also includes a second resolver angle value, wherein the second resolver angle value is obtained in the following manner: when the motor is in a no-load state, the first control instruction is output; the first voltage control instruction is output to increase the quadrature-axis voltage by controlling the quadrature-axis injection current; when it is monitored that the quadrature-axis current increases to a second specified current value, the third voltage control instruction is output, and the angle value detected by the resolver sensor within the preset time length is continuously acquired to average all the angle values ​​detected within the preset time length to obtain the second resolver angle value; and the fourth voltage control instruction is output to reduce the quadrature-axis voltage to zero.

[0007] In a possible implementation, the second current control instruction indicates that the quadrature-axis current value is controlled to be zero, the second condition indicates that the quadrature-axis voltage output is a voltage value corresponding to the quadrature-axis current value of zero, the second voltage control instruction indicates that the direct-axis voltage is controlled to be increased, and the second angle value includes a third resolver angle value, wherein the third resolver angle value is obtained in the following manner: when the motor is in a no-load state, the second control instruction is output to fix the quadrature-axis voltage output to a voltage value corresponding to the quadrature-axis current value of zero; the second voltage control instruction is output to increase the direct-axis voltage by controlling the direct-axis injection current; when it is monitored that the direct-axis current increases to a third specified current value, a fifth voltage control instruction for stopping the increase of the direct-axis voltage is output, and the angle value detected by the resolver sensor within a preset time length is continuously obtained, so as to average all the angle values ​​detected within the preset time length to obtain the third resolver angle value; and a sixth voltage control instruction for controlling the direct-axis voltage to decrease is output to decrease the direct-axis voltage to zero.

[0008] In a possible implementation, the second angle value also includes a fourth resolver angle value, wherein the fourth resolver angle value is obtained in the following manner: when the motor is in a no-load state, the second control instruction is output to fix the quadrature-axis voltage output to a voltage value corresponding to the quadrature-axis current value of zero; the second voltage control instruction is output to increase the direct-axis voltage by controlling the direct-axis injection current; when it is monitored that the direct-axis current increases to a fourth specified current value, the fifth voltage control instruction is output, and the angle value detected by the resolver sensor within the preset time length is continuously acquired to average all angle values ​​detected within the preset time length to obtain the fourth resolver angle value; and the sixth voltage control instruction is output to drop the direct-axis voltage to zero.

[0009] In a possible implementation, the resolver zero point of the resolver sensor is calibrated in the following manner: based on all resolver angle values, the influence of the cross-axis current on the change trend of the resolver angle value is determined, so as to obtain the resolver zero point initial value based on the change trend; the resolver zero point initial value is input into the closed-loop regulator of the motor to obtain the resolver zero point fine-tuning value, and the resolver zero point fine-tuning value and the resolver zero point initial value are stored, so as to calibrate the resolver zero point based on the resolver zero point initial value and the resolver zero point fine-tuning value.

[0010] In a possible implementation manner, the resolver zero point initial value is obtained according to the influence of the change trend in the following manner: if the quadrature-axis current increases the resolver angle value, 180 degrees are subtracted from the sum of all resolver angle values ​​and the result is divided by the number of resolver angle values ​​to obtain the resolver zero point initial value; if the quadrature-axis current decreases the resolver angle value, 180 degrees are added to the sum of all resolver angle values ​​and the result is divided by the number of resolver angle values ​​to obtain the resolver zero point initial value.

[0011] In a possible implementation, the influence of the quadrature-axis current on the changing trend of the resolver angle value is determined in the following manner: when the first resolver angle value is greater than the third resolver angle value, and the second resolver angle value is greater than the fourth resolver angle value, it is determined that the quadrature-axis current increases the resolver angle value; when the first resolver angle value is less than the third resolver angle value, and the second resolver angle value is less than the fourth resolver angle value, it is determined that the quadrature-axis current decreases the resolver angle value.

[0012] In a possible implementation, the resolver zero point fine-tuning value is obtained in the following manner: outputting a third current control instruction for controlling the quadrature-axis current value and the direct-axis current value, and causing the motor to perform current closed-loop regulation, the third current control instruction indicating that the quadrature-axis current value and the direct-axis current value are controlled to be zero; sending a speed instruction to a dynamometer so that the dynamometer drags the motor to run at a constant speed; outputting an instruction for adjusting the direct-axis voltage smoothing filter coefficient to smooth the direct-axis voltage; using the resolver zero point initial value as the initial value of the closed-loop regulator, so that the smoothed direct-axis voltage follows the desired direct-axis voltage through the closed-loop regulator, and outputting the resolver zero point fine-tuning value after the closed-loop regulator is stable.

[0013] In a second aspect, the present application provides a resolver zero point calibration device, the device comprising: a first control module, used to perform the following control steps for the quadrature axis of the motor: when the motor is in a no-load state, output a first control instruction, the first control instruction comprising a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct-axis current value of the motor; when it is monitored that the output voltage of the direct-axis of the motor meets a first condition, output a first voltage control instruction for controlling the quadrature-axis voltage value of the motor; after the rotor position of the motor is stable, the resolver angle value detected by the resolver sensor is used to obtain a first angle value corresponding to the quadrature axis; a second control module, used to perform the following control steps for the quadrature axis of the motor: when the motor is in a no-load state, output a first control instruction, the first control instruction comprising a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct-axis current value of the motor; when it is monitored that the output voltage of the direct-axis of the motor meets a first condition, output a first voltage control instruction for controlling the quadrature-axis voltage value of the motor; after the rotor position of the motor is stable, the first angle value corresponding to the quadrature axis is obtained according to the resolver angle value detected by the resolver sensor; The direct axis of the motor performs the following control steps: when the motor is in a no-load state, output a second control instruction, the second control instruction includes the first rotor control instruction and a second current control instruction for controlling the quadrature-axis current value of the motor; when it is monitored that the output voltage of the quadrature-axis of the motor meets the second condition, output a second voltage control instruction for controlling the direct axis voltage value of the motor; after the rotor position is stable, obtain a second angle value corresponding to the direct axis according to the resolver angle value detected by the resolver sensor; a determination module is used to calibrate the resolver zero point of the resolver sensor according to the first angle value and the second angle value, so that the resolver zero point corresponds to the rotor position zero point of the motor.

[0014] The present application provides a method and device for calibrating a resolver zero point, wherein the method comprises: executing the following control steps for the quadrature axis of a motor: when the motor is in a no-load state, outputting a first control instruction, and when it is monitored that the output voltage of the direct axis of the motor meets a first condition, outputting a first voltage control instruction, and after the rotor position of the motor is stabilized, obtaining a first angle value corresponding to the quadrature axis according to the resolver angle value detected by the resolver sensor; executing the following control steps for the direct axis of the motor: outputting a second control instruction, and when it is monitored that the output voltage of the quadrature axis of the motor meets a second condition, outputting a second voltage control instruction, and after the rotor position of the motor is stabilized, obtaining a first angle value corresponding to the direct axis according to the resolver angle value detected by the resolver sensor; calibrating the resolver zero point according to the first angle value and the second angle value.

[0015] The beneficial effects of the resolver zero point calibration solution of the present application are as follows: By executing control strategies on the quadrature axis and direct axis of the motor respectively, the rapid positioning of the zero point of the resolver is achieved, and calibration is performed based on the two angle values ​​obtained from the quadrature axis and the direct axis, thereby improving the calibration efficiency and accuracy.

[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A flowchart of a resolver zero point calibration method provided in an embodiment of the present application; Figure 2 A flow chart for calibrating the zero point of a resolver provided in an embodiment of the present application; Figure 3 A flow chart for obtaining a resolver zero point fine-tuning value provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a resolver zero point calibration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0020] First, the application scenarios to which the present application is applicable are introduced. The present application can be applied to motor technology.

[0021] Vector control is the core strategy of AC motor control, and its accuracy is highly dependent on the accurate perception of the motor rotor position. Real-time and accurate feedback of the rotor position is the prerequisite for achieving efficient and stable torque control. Any deviation in position information will directly affect the performance of the control system, including but not limited to the accuracy of torque output, the dynamic response and stability of the current regulator, and in extreme cases, the activation of the driver overcurrent protection mechanism, resulting in equipment damage or system shutdown. As a key sensor for obtaining motor rotor position information, the working principle of the resolver is based on electromagnetic induction, and it can continuously and reliably provide the absolute angle information of the rotor. However, the accurate setting of the resolver zero point is a challenge, because the mechanical zero point of the resolver often does not coincide with the actual mechanical zero point of the motor rotor. What's more complicated is that under certain specific conditions, the direction of change of the resolver signal may be opposite to the actual rotation direction of the rotor, which further increases the complexity of interpreting the position information. Accurate calibration of the resolver zero point is a key step in the parameter setting of the motor controller. Correct zero point calibration can ensure that the control system accurately understands the relationship between the resolver signal and the actual position of the rotor, and is the basis for achieving high-performance vector control. Currently, the methods for calibrating the resolver zero point mainly rely on advanced algorithms or specific test conditions, such as applying a large braking torque to observe the system response. These methods place high demands on the computing power and accuracy of the control algorithm and the stability of the calibration environment.

[0022] Based on this, an embodiment of the present application provides a method and device for calibrating the zero point of a resolver, which aims to accurately calibrate the zero point of a motor resolver, and can be simplified to the calibration of the motor free sliding condition without dragging the motor.

[0023] See also Figure 1 , Figure 1 The flowchart of a resolver zero point calibration method provided in the embodiment of the present application is as follows. Figure 1 As shown in , the resolver zero point calibration method provided in the embodiment of the present application includes: S101. Execute the following control steps for the quadrature axis of the motor: when the motor is in a no-load state, output a first control instruction; when it is monitored that the output voltage of the direct axis of the motor meets a first condition, output a first voltage control instruction for controlling the quadrature axis voltage value of the motor; after the rotor position of the motor is stable, obtain a first angle value corresponding to the quadrature axis based on the angle value detected by the resolver sensor.

[0024] Here, the first control instruction includes a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct-axis current value of the motor. The first rotor control instruction indicates that the rotor angle value is controlled to zero, the first current control instruction indicates that the direct-axis current value is controlled to zero, the first condition indicates that the direct-axis voltage output is a voltage value corresponding to the direct-axis current value of zero, and the first voltage control instruction indicates that the quadrature-axis voltage is controlled to be increased.

[0025] As an example, before calibration, the motor needs to be mechanically disconnected from the dynamometer so that the motor has no external load and can rotate freely. The rotor position angle value used for coordinate transformation in motor control is switched to a manual value. At the same time, the DQ current regulator is output in voltage accumulation mode, and the voltage is not increased or decreased according to the current feedback value.

[0026] In a preferred example of the present application, the first angle value includes a first rotary angle value and a second rotary angle value, and the first rotary angle value can be obtained in the following manner: when the motor is in a no-load state, a first control instruction is output to fix the direct-axis voltage output to a voltage value corresponding to a direct-axis current value of zero; a first voltage control instruction is output to control the increase of the quadrature-axis voltage so that the quadrature-axis is injected into the current; when it is monitored that the quadrature-axis current increases to a first specified current value, a third voltage control instruction is output to stop increasing the quadrature-axis voltage, and the angle value detected by the rotary sensor within a preset time length is continuously obtained to average all angle values ​​detected within the preset time length to obtain the first rotary angle value; a fourth voltage control instruction is output to control the quadrature-axis voltage to drop so that the quadrature-axis voltage drops to zero.

[0027] Among them, the process of obtaining the second resolver angle value is the same as described above. When monitoring the quadrature-axis current, the quadrature-axis voltage is adjusted only after it reaches the second specified current value. The second specified current value here can be the same as the first specified current value, and the reliability of the first angle value is enhanced by repeated measurements.

[0028] Here, the first specified current value and the second specified current value may be a certain fixed multiple of the rated current of the motor, and the preset time length may be set to 2s.

[0029] S102, executing the following control steps for the direct axis of the motor: when the motor is in a no-load state, outputting a second control instruction to fix the quadrature-axis voltage output to a voltage value corresponding to a quadrature-axis current value of zero; outputting a second voltage control instruction to increase the direct axis voltage by controlling the direct axis injection current; when monitoring that the direct axis current increases to a third specified current value, outputting a fifth voltage control instruction for stopping increasing the direct axis voltage, and continuously acquiring the angle value detected by the resolver sensor within a preset time length, so as to average all the angle values ​​detected within the preset time length to obtain a third resolver angle value; outputting a sixth voltage control instruction for controlling the direct axis voltage to drop, so as to drop the direct axis voltage to zero.

[0030] Here, the second control instruction includes a first rotor control instruction and a second current control instruction for controlling the quadrature-axis current value of the motor, the second current control instruction indicates that the quadrature-axis current value is controlled to be zero, the second condition indicates that the quadrature-axis voltage output is a voltage value corresponding to the quadrature-axis current value of zero, and the second voltage control instruction indicates that the direct-axis voltage is controlled to be increased.

[0031] In a preferred example of the present application, the second angle value includes a third rotation angle value and a fourth rotation angle value.

[0032] Among them, the third resolver angle value is obtained in the following manner: when the motor is in a no-load state, a second control instruction is output to fix the quadrature-axis voltage output to a voltage value corresponding to a quadrature-axis current value of zero; a second voltage control instruction is output to adjust the direct-axis current; the direct-axis current is monitored, and when the direct-axis current rises to a third specified current value, the direct-axis voltage is stopped from being increased, and the resolver angle value detected by the resolver sensor within a preset time length is continuously obtained, so that all angle values ​​detected within the preset time length are averaged to obtain the third resolver angle value; and a fourth voltage control instruction for changing the direct-axis voltage is output to drop the direct-axis voltage to zero.

[0033] The process of obtaining the fourth resolver angle value is the same as described above, and the third specified current value here may be the same as the fourth specified current value, in order to enhance the reliability of the second angle value through repeated measurements.

[0034] As an example, if there is a phenomenon that all the rotation angle values ​​cross 0° or 360°, the rotation angle values ​​that cross 0° or 360° are recalculated.

[0035] S103: Calibrate the resolver zero point of the resolver sensor according to the first angle value and the second angle value, so that the resolver zero point corresponds to the rotor position zero point of the motor.

[0036] Below through Figure 2 This paper introduces the specific process of calibrating the resolver zero point.

[0037] See also Figure 2 , Figure 2 A flow chart for calibrating the zero point of a resolver provided in an embodiment of the present application.

[0038] S201. Determine the influence of the quadrature-axis current on the change trend of the resolver angle value according to all resolver angle values, so as to obtain the resolver zero point initial value according to the change trend influence.

[0039] Here, the resolver zero point initial value can be calculated based on the influence of the quadrature-axis current on the change trend of the resolver angle value.

[0040] If the quadrature-axis current increases the resolver angle value, then the sum of all resolver angle values ​​is subtracted by 180 degrees and divided by the number of resolver angle values ​​to obtain the resolver zero point initial value.

[0041] At this time, the motor rotor position θ can be calculated by formula (1): θ=θ sensor -θ0(1) where θ sensor is the resolver angle value obtained by the resolver decoding chip, and θ0 is the resolver zero point initial value.

[0042] In a preferred example of the present application, when the first resolver angle value is greater than the third resolver angle value, and the second resolver angle value is greater than the fourth resolver angle value, it is determined that the quadrature-axis current increases the resolver angle value.

[0043] If the quadrature-axis current reduces the resolver angle value, then the sum of all resolver angle values ​​is added with 180 degrees and divided by the number of resolver angle values ​​to obtain the resolver zero point initial value.

[0044] At this time, the motor rotor position θ can be calculated by formula (2): θ=θ0-θ sensor (2) In a preferred example of the present application, when the first resolver angle value is smaller than the third resolver angle value, and the second resolver angle value is smaller than the fourth resolver angle value, the quadrature-axis current is determined to reduce the resolver angle value.

[0045] S202, inputting the resolver zero point initial value into the closed-loop regulator of the motor to obtain the resolver zero point fine-tuning value, and storing the resolver zero point fine-tuning value and the resolver zero point initial value, so as to calibrate the resolver zero point according to the resolver zero point initial value and the resolver zero point fine-tuning value.

[0046] Below through Figure 3 The specific process of obtaining the resolver zero point fine-tuning value is introduced.

[0047] See also Figure 3 , Figure 3 A flow chart for obtaining a resolver zero point fine-tuning value provided in an embodiment of the present application.

[0048] As an example, before performing the resolver zero point calibration, the motor needs to be firmly and rigidly connected to the dynamometer so that the dynamometer can effectively drive the motor to run at a constant speed. Next, in the settings of the motor controller, the calculation method of the rotor position angle value θ is input, that is, formula (1) and formula (2) are input to the motor controller. At this time, the DQ current regulator will adopt a standard closed-loop regulation method, abandon the cumulative output mode, and instead use the manual given mode command to ensure the accuracy and controllability of the regulation process.

[0049] S301, outputting a third current control instruction for controlling the quadrature-axis current value and the direct-axis current value, and making the motor perform current closed-loop regulation.

[0050] Here, the third current control instruction indicates controlling the quadrature axis current value and the direct axis current value to be zero; S302: Send a speed command to the dynamometer to make the dynamometer drive the motor to run at a constant speed.

[0051] S303: Output an instruction for adjusting the direct-axis voltage smoothing filter coefficient to smooth the direct-axis voltage.

[0052] S304, using the resolver zero point initial value as the initial value of the closed-loop regulator, so that the smoothed direct-axis voltage follows the direct-axis desired voltage through the closed-loop regulator, and outputting the resolver zero point fine-tuning value after the closed-loop regulator is stable.

[0053] Here, the direct-axis desired voltage is a reference signal for magnetic field alignment and is 0. After the output of the closed-loop regulator is stabilized, the resolver zero point initial value and the resolver zero point fine-tuning value are stored and recorded in the calibration data.

[0054] Based on the same inventive concept, a resolver zero point calibration device corresponding to the resolver zero point calibration method is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned resolver zero point calibration method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0055] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of the resolver zero point calibration device provided in the embodiment of the present application. Figure 4 As shown in , the resolver zero point calibration device 400 includes: The first control module 401 is used to perform the following control steps for the quadrature axis of the motor: when the motor is in a no-load state, output a first control instruction, the first control instruction includes a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct axis current value of the motor; when it is monitored that the output voltage of the direct axis of the motor meets a first condition, output a first voltage control instruction for controlling the quadrature axis voltage value of the motor; after the rotor position of the motor is stable, obtain a first angle value corresponding to the quadrature axis according to the resolver angle value detected by the resolver sensor; The second control module 402 is used to execute the following control steps for the direct axis of the motor: when the motor is in a no-load state, output a second control instruction, the second control instruction includes the first rotor control instruction and a second current control instruction for controlling the quadrature axis current value of the motor; when it is monitored that the output voltage of the quadrature axis of the motor meets the second condition, output a second voltage control instruction for controlling the direct axis voltage value; after the rotor position of the motor is stabilized, the first angle corresponding to the direct axis is obtained according to the resolver angle value detected by the resolver sensor.

[0056] The determination module 403 is used to determine the resolver zero point of the resolver sensor according to the first angle value and the second angle value, so that the resolver zero point corresponds to the rotor position zero point of the motor.

[0057] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0058] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0059] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0060] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0061] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0062] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A resolver zero point calibration method, characterized in that: The method comprises: The following control steps are performed for the quadrature axis of the motor: when the motor is in a no-load state, a first control instruction is output, the first control instruction includes a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct axis current value of the motor; when it is monitored that the output voltage of the direct axis of the motor meets a first condition, a first voltage control instruction for controlling the quadrature axis voltage value of the motor is output; after the rotor position of the motor is stable, a first angle value corresponding to the quadrature axis is obtained according to the angle value detected by the resolver sensor; The following control steps are performed for the direct axis of the motor: when the motor is in a no-load state, a second control instruction is output, the second control instruction includes the first rotor control instruction and a second current control instruction for controlling the quadrature axis current value of the motor; when it is monitored that the output voltage of the quadrature axis of the motor meets the second condition, a second voltage control instruction for controlling the direct axis voltage value of the motor is output; after the rotor position is stable, a second angle value corresponding to the direct axis is obtained according to the angle value detected by the resolver sensor; The resolver zero point of the resolver sensor is calibrated according to the first angle value and the second angle value so that the resolver zero point corresponds to the rotor position zero point of the motor.

2. The method according to claim 1, characterized in that The first rotor control instruction indicates that the rotor angle value is controlled to be zero, the first current control instruction indicates that the direct axis current value is controlled to be zero, the first condition indicates that the direct axis voltage output is a voltage value corresponding to the direct axis current value being zero, the first voltage control instruction indicates that the quadrature axis voltage is controlled to be increased, and the first angle value includes a first resolver angle value. The first rotation angle value is obtained by: When the motor is in a no-load state, outputting the first control instruction so that the direct-axis voltage output is fixed to a voltage value corresponding to the direct-axis current value being zero; Outputting the first voltage control instruction to increase the quadrature-axis voltage by controlling so that the quadrature-axis injects current; When it is monitored that the quadrature-axis current increases to a first specified current value, a third voltage control instruction for stopping increasing the quadrature-axis voltage is output, and the angle value detected by the resolver sensor within a preset time length is continuously acquired, so as to average all the angle values ​​detected within the preset time length to obtain the first resolver angle value; A fourth voltage control instruction for controlling the quadrature-axis voltage to decrease is output, so that the quadrature-axis voltage decreases to zero.

3. The method according to claim 2, characterized in that The first angle value also includes a second rotation angle value, The second rotation angle value is obtained by: When the motor is in a no-load state, outputting the first control instruction; Outputting the first voltage control instruction to increase the quadrature-axis voltage by controlling so that the quadrature-axis injects current; When it is monitored that the quadrature-axis current increases to a second specified current value, the third voltage control instruction is output, and the angle value detected by the resolver sensor within the preset time length is continuously acquired, so as to average all the angle values ​​detected within the preset time length to obtain the second resolver angle value; The fourth voltage control instruction is output to reduce the quadrature-axis voltage to zero.

4. The method according to claim 1, characterized in that: The second current control instruction indicates that the quadrature-axis current value is controlled to be zero, the second condition indicates that the quadrature-axis voltage output is a voltage value corresponding to the quadrature-axis current value being zero, the second voltage control instruction indicates that the direct-axis voltage is controlled to be increased, and the second angle value includes a third resolver angle value. The third rotation angle value is obtained by: When the motor is in a no-load state, outputting the second control instruction so that the quadrature-axis voltage output is fixed to a voltage value corresponding to zero quadrature-axis current value; Outputting the second voltage control instruction to increase the direct-axis voltage by controlling so as to inject the direct-axis current; When it is monitored that the direct-axis current increases to a third specified current value, a fifth voltage control instruction for stopping increasing the direct-axis voltage is output, and the angle value detected by the resolver sensor within a preset time length is continuously acquired, so as to average all the angle values ​​detected within the preset time length to obtain the third resolver angle value; A sixth voltage control instruction for controlling the direct-axis voltage to drop is output, so that the direct-axis voltage drops to zero.

5. The method according to claim 4, characterized in that The second angle value also includes a fourth rotation angle value, The fourth rotation angle value is obtained by: When the motor is in a no-load state, outputting the second control instruction so that the quadrature-axis voltage output is fixed to a voltage value corresponding to zero quadrature-axis current value; Outputting the second voltage control instruction to increase the direct-axis voltage by controlling so as to inject the direct-axis current; When it is monitored that the direct-axis current increases to a fourth specified current value, the fifth voltage control instruction is output, and the angle value detected by the resolver sensor within the preset time length is continuously acquired, so as to average all the angle values ​​detected within the preset time length to obtain the fourth resolver angle value; The sixth voltage control instruction is output to reduce the direct-axis voltage to zero.

6. The method according to claim 1, characterized in that The resolver zero point of the resolver sensor is calibrated in the following manner: According to all resolver angle values, determining the influence of the quadrature-axis current on the variation trend of the resolver angle value, so as to obtain the resolver zero point initial value according to the influence of the variation trend; The resolver zero point initial value is input into the closed-loop regulator of the motor to obtain a resolver zero point fine-tuning value, and the resolver zero point fine-tuning value and the resolver zero point initial value are stored to calibrate the resolver zero point according to the resolver zero point initial value and the resolver zero point fine-tuning value.

7. The method according to claim 6, characterized in that The resolver zero point initial value is obtained according to the influence of the change trend in the following manner: If the quadrature-axis current increases the resolver angle value, then the sum of all resolver angle values ​​is subtracted by 180 degrees and divided by the number of resolver angle values ​​to obtain the resolver zero point initial value; If the quadrature-axis current reduces the resolver angle value, then the sum of all resolver angle values ​​is added with 180 degrees and divided by the number of the resolver angle values ​​to obtain the resolver zero point initial value.

8. The method according to claim 7, characterized in that The influence of the quadrature-axis current on the change trend of the resolver angle value is determined by: When the first resolver angle value is greater than the third resolver angle value, and the second resolver angle value is greater than the fourth resolver angle value, determining that the quadrature-axis current increases the resolver angle value; When the first resolver angle value is smaller than the third resolver angle value, and the second resolver angle value is smaller than the fourth resolver angle value, determining the quadrature-axis current reduces the resolver angle value.

9. The method according to claim 6, characterized in that The resolver zero point fine-tuning value is obtained by: Outputting a third current control instruction for controlling the quadrature-axis current value and the direct-axis current value, and causing the motor to perform current closed-loop regulation, wherein the third current control instruction indicates controlling the quadrature-axis current value and the direct-axis current value to be zero; Sending a speed command to the dynamometer so that the dynamometer drives the motor to run at a constant speed; Outputting an instruction for adjusting a direct-axis voltage smoothing filter coefficient to smooth the direct-axis voltage; The resolver zero point initial value is used as the initial value of the closed-loop regulator, so that the smoothed direct-axis voltage follows the direct-axis desired voltage through the closed-loop regulator, and the resolver zero point fine-tuning value is output after the closed-loop regulator is stabilized.

10. A resolver zero point calibration device, characterized in that: The device comprises: A first control module is used to perform the following control steps for the quadrature axis of the motor: when the motor is in a no-load state, output a first control instruction, the first control instruction includes a first rotor control instruction for controlling the rotor angle value of the motor and a first current control instruction for controlling the direct axis current value of the motor; when it is monitored that the output voltage of the direct axis of the motor meets a first condition, output a first voltage control instruction for controlling the quadrature axis voltage value of the motor; after the rotor position of the motor is stable, a first angle value corresponding to the quadrature axis is obtained according to the resolver angle value detected by the resolver sensor; A second control module is used to perform the following control steps for the direct axis of the motor: when the motor is in a no-load state, output a second control instruction, the second control instruction includes the first rotor control instruction and a second current control instruction for controlling the quadrature axis current value of the motor, when it is monitored that the output voltage of the quadrature axis of the motor meets a second condition, output a second voltage control instruction for controlling the direct axis voltage value of the motor, after the rotor position is stable, according to the resolver angle value detected by the resolver sensor, to obtain a second angle value corresponding to the direct axis; A determination module is used to calibrate the resolver zero point of the resolver sensor according to the first angle value and the second angle value, so that the resolver zero point corresponds to the rotor position zero point of the motor.

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