A method of positioning a motor encoder

Abstract

The application relates to the motor technical field, and discloses a positioning method of a motor encoder. The method comprises the following steps: before the motor encoder is removed, the relative position between a rotating shaft of the motor encoder and a motor rotor dummy shaft of a motor is marked; the rotating shaft of the motor encoder is installed on the motor rotor dummy shaft of the motor according to the marked relative position; after the motor encoder is installed, the motor encoder is positioned according to an offset angle of the motor encoder. The technical scheme of the embodiment of the application can improve the positioning accuracy and efficiency of the motor encoder, so as to guarantee the stability of the motor during operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular, to a positioning method of an electric machine encoder. BACKGROUND

[0002] At present, when large-scale maintenance is performed on a synchronous electric machine, original positioning of the synchronous electric machine encoder requires manual work of using a travelling crane to rotate a shaft, which not only has problems of low efficiency and poor accuracy, but also has safety hazards. Based on this, how to efficiently and accurately position the synchronous electric machine encoder to ensure stable operation of the synchronous electric machine is a technical problem to be solved. SUMMARY

[0003] The present application aims to provide a positioning method of an electric machine encoder, thereby improving the accuracy and efficiency of positioning of the electric machine encoder to ensure the stability of the electric machine during operation.

[0004] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0005] According to an aspect of an embodiment of the present application, a positioning method of an electric machine encoder is provided, which comprises: before removing the electric machine encoder, marking a relative position between a rotating shaft of the electric machine encoder and a motor rotor dummy shaft of a motor; installing the electric machine encoder, and installing the rotating shaft of the electric machine encoder on the motor rotor dummy shaft of the motor according to the marked relative position; after installing the electric machine encoder, positioning the electric machine encoder according to an offset angle of the electric machine encoder.

[0006] In some embodiments of the present application, based on the foregoing scheme, before installing the electric machine encoder, the method further comprises: fixing the rotating shaft.

[0007] In an embodiment of the present application, based on the foregoing scheme, the positioning of the electric machine encoder according to the offset angle of the electric machine encoder comprises: measuring the offset angle of the electric machine encoder in a first stage to obtain a first offset angle; recording the first offset angle into a transmission control system, so that a PLC controller controls the motor to realize motor start-stop, forward and reverse rotation, and set-speed constant-speed operation, to realize preliminary positioning of the electric machine encoder.

[0008] In an embodiment of the present application, based on the foregoing scheme, the first-stage measurement of the offset angle of the motor encoder to obtain the first offset angle comprises: in the first-stage measurement of the offset angle of the motor encoder, the PLC controller sends an EXT operation instruction to the frequency converter, and the frequency converter performs the first-stage measurement of the offset angle of the motor encoder to obtain the first offset angle after receiving the EXT operation instruction.

[0009] In an embodiment of the present application, based on the foregoing scheme, the first-stage measurement of the offset angle of the motor encoder to obtain the first offset angle comprises: triggering a low-speed measurement mode, in which the speed control amount in the EXT operation instruction is shielded, and a constant current is applied to the motor stator and the excitation circuit to control the motor to rotate at a low speed, so as to measure the offset angle in the low-speed measurement mode; triggering a high-speed measurement mode, in which, on the basis of the offset angle in the low-speed measurement mode, the motor is controlled to automatically accelerate to the base speed of the motor when the motor rotates forward and reversely, and the offset angle in the high-speed measurement mode is measured as the first offset angle according to the angle deviation of the output voltage of the frequency converter.

[0010] In an embodiment of the present application, based on the foregoing scheme, after the PLC controller controls the motor to realize motor start-stop, forward and reverse rotation, and constant-speed operation at a set speed, the method further comprises: correcting the coaxiality of the motor encoder and the motor rotor, and performing a second-stage measurement of the offset angle of the motor encoder to obtain a second offset angle; and recording the second offset angle in the transmission control system to realize the final positioning of the motor encoder.

[0011] In an embodiment of the present application, based on the foregoing scheme, the correction of the coaxiality of the motor encoder and the motor rotor is ≤0.05 mm.

[0012] In an embodiment of the present application, based on the foregoing scheme, the second-stage measurement of the offset angle of the motor encoder to obtain the second offset angle comprises: continuously measuring the offset angle of the motor encoder twice to obtain two offset angle measurement values; and if the deviation of the two offset angle measurement values is less than or equal to a preset difference value, the offset angle measurement value is determined as the second offset angle.

[0013] In an embodiment of the present application, based on the foregoing scheme, the preset difference value is 1°.

[0014] In an embodiment of the present application, based on the foregoing scheme, the motor comprises a synchronous motor in a rough rolling R1R2 rolling mill or a finishing rolling F1-F7 rolling mill.

[0015] In the technical scheme of the embodiment of the present application, the relative position between the rotating shaft of the motor encoder and the motor rotor dummy shaft of the motor is marked before the motor encoder is disassembled, then the motor encoder is installed, the rotating shaft of the motor encoder is installed on the motor rotor dummy shaft of the motor according to the marked relative position, and after the motor encoder is installed, the motor encoder is positioned according to the offset angle of the motor encoder. In this way, the relative position of the motor encoder is marked and the offset angle is checked to quickly and effectively position the motor encoder, so that the motor can stably work after maintenance.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. It is clear that the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor. In the drawings:

[0018] Figure 1 The flow chart of the positioning method of the motor encoder according to the embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the examples set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art.

[0020] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the present application. One skilled in the relevant art will recognize, however, that the techniques of the present application can be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the present application.

[0021] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0023] The implementation details of the technical solutions in the embodiments of this application are described in detail below:

[0024] See Figure 1 , Figure 1 This is a flowchart illustrating a positioning method for a motor encoder according to an embodiment of this application. When positioning the motor encoder, the method is combined with... Figure 1 You can proceed with the following steps:

[0025] Step 110: Before removing the motor encoder, mark the relative position between the rotating shaft of the motor encoder and the dummy shaft of the motor rotor.

[0026] Step 120: Install the motor encoder by mounting the rotating shaft of the motor encoder onto the dummy shaft of the motor rotor according to the relative positions marked.

[0027] Step 130: After installing the motor encoder, position the motor encoder according to its offset angle.

[0028] In one embodiment of this application, the relative position between the rotating shaft of the motor encoder and the dummy shaft of the motor rotor can be marked by drawing marks or affixing labels, etc., as a reference mark when the motor encoder is reinstalled. This ensures that the relative displacement between the rotating shaft of the motor encoder and the dummy shaft of the motor rotor after removal and reinstallation is as close to zero as possible, so that the offset angle generated by the motor encoder after maintenance is also as close to zero as possible, thus achieving coarse adjustment of the offset angle.

[0029] In this application, based on step 120, the rotating shaft can be fixed before installing the motor encoder.

[0030] In one embodiment of this application, fixing the rotating shaft can further achieve coarse adjustment of the offset angle, preventing the rotating shaft from returning to its initial position after a full rotation when it is not fixed. Therefore, fixing the rotating shaft can better ensure that the offset angle generated by the motor encoder after maintenance is as close to zero as possible.

[0031] Continue to combine Figure 1 The step of positioning the motor encoder based on the offset angle of the motor encoder may specifically include: measuring the offset angle of the motor encoder in the first stage to obtain a first offset angle; inputting the first offset angle into the transmission control system, so that the PLC controller controls the motor to start and stop the motor, reverse the motor, and run at a set constant speed, so as to achieve the initial positioning of the motor encoder.

[0032] Furthermore, the first stage measurement of the offset angle of the motor encoder to obtain the first offset angle may include: in the first stage measurement of the offset angle of the motor encoder, the PLC controller sends an EXT operation command to the frequency converter, and after receiving the EXT operation command, the frequency converter performs the first stage measurement of the offset angle of the motor encoder to obtain the first offset angle.

[0033] Specifically, the first stage of measuring the offset angle of the motor encoder to obtain the first offset angle may further include: triggering a low-speed measurement mode, in which the speed control quantity in the EXT operation command is disabled, and a constant current is applied to the motor stator and excitation circuit to control the motor to rotate at low speed, and the offset angle in the low-speed measurement mode is measured; triggering a high-speed measurement mode, in which, based on the offset angle in the low-speed measurement mode, when the motor is controlled to automatically accelerate to the motor base speed in both forward and reverse directions, the offset angle in the high-speed measurement mode is measured according to the angle deviation of the inverter output voltage, and this is taken as the first offset angle.

[0034] In one embodiment of this application, the following is continued: Figure 1 During step 130, it can be ensured that the motor encoder has completed the coarse adjustment of the offset angle before reinstallation. After the motor encoder is reinstalled, the PLC controller sends an EXT operation command to the frequency converter. After receiving the EXT operation command, the frequency converter controls the motor to run in low-speed measurement mode. During this process, the frequency converter will shield the speed control quantity in the EXT operation command and apply a constant current to the motor stator and excitation circuit to control the motor to rotate at low speed. In this case, the offset angle can be measured to detect whether the frequency converter and the encoder can operate normally.

[0035] After confirming that the frequency converter and the encoder are in normal operation, a high-speed measurement mode is triggered by the frequency converter to automatically accelerate the motor to the motor base speed to ensure that the subsequent measured offset angle value is more accurate. At this time, the rotation direction of the motor can be forward or reverse. At this time, the frequency converter compares the motor rotation angle obtained by itself with the motor rotation angle obtained by the encoder and outputs the real-time offset angle, i.e., the first offset angle. Although the value of the first offset angle has been controlled in a smaller range and tends to zero as much as possible after rough adjustment, in order to make the motor run more stably, the offset angle of the motor still needs to be fine-tuned on the basis of the first offset angle. Before fine-tuning, the first offset angle is recorded into the transmission control system.

[0036] In the present application, after the PLC controller controls the motor to realize motor start-stop, forward and reverse rotation, and constant speed operation at a set speed, the motor encoder and the motor rotor can be corrected for coaxiality, and the offset angle of the motor encoder can be measured in a second stage to obtain a second offset angle. The second offset angle is recorded into the transmission control system to realize the final positioning of the motor encoder.

[0037] In an embodiment of the present application, the set speed can be 10% of the rated speed of the motor. Based on the obtained first offset angle, the coaxiality of the motor encoder and the motor rotor is corrected to fine-tune the offset angle of the motor, so that the second offset angle generated by the motor encoder is smaller and more accurate relative to the first offset angle, to ensure that the motor has higher stability.

[0038] In the present application, the coaxiality of the motor encoder and the motor rotor can be corrected to be ≤0.05mm.

[0039] Further, the second-stage measurement of the offset angle of the motor encoder to obtain the second offset angle can specifically include: continuously measuring the offset angle of the motor encoder twice to obtain two offset angle measurement values; if the deviation of the two offset angle measurement values is less than or equal to a preset difference value, the offset angle measurement value is determined as the second offset angle.

[0040] Specifically, the preset difference value can be 1°.

[0041] In one embodiment of the present application, after the coaxiality correction is completed, the motor can be started to measure the fine-tuned offset angle twice, for example, the values of the fine-tuned offset angle measured twice are 2.5° and 3° respectively, since the difference between 2.5° and 3° is less than 1°, the coaxiality correction is successful, and the value of the offset angle measured the second time after fine-tuning (herein referred to as 3°) can be recorded as the second offset angle in the transmission control system, thus, the final positioning of the motor encoder is completed.

[0042] In the present application, the motor includes a synchronous motor in the rough rolling R1R2 rolling mill or the finishing rolling F1-F7 rolling mill.

[0043] In summary, in the technical solution of the embodiment of the present application, before the motor encoder is removed, the relative position between the rotating shaft of the motor encoder and the motor rotor dummy shaft of the motor is marked, then the motor encoder is installed, the rotating shaft of the motor encoder is installed on the motor rotor dummy shaft of the motor according to the marked relative position, and after the motor encoder is installed, the motor encoder is positioned according to the offset angle of the motor encoder. In this way, by marking the relative position of the motor encoder and checking the offset angle, the motor encoder is quickly and effectively positioned, and the motor can stably work after maintenance.

[0044] In addition, the above-described figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not for limiting purposes. It is easy to understand that the processes shown in the above-described figures do not indicate or limit the time sequence of the processes. In addition, it is also easy to understand that the processes can be executed synchronously or asynchronously, for example, in multiple modules.

[0045] It should be understood that the present application is not limited to the precise construction which has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is limited only by the claims which follow.

Claims

1. A method of positioning a motor encoder, characterized by, The method comprises: Before removing the motor encoder, marking the relative position between the rotating shaft of the motor encoder and the motor rotor dummy shaft of the motor; installing the motor encoder, and installing the rotating shaft of the motor encoder on the motor rotor dummy shaft of the motor according to the marked relative position; After installing the motor encoder, positioning the motor encoder according to the offset angle of the motor encoder; The positioning of the motor encoder according to the offset angle of the motor encoder comprises: In the first stage of measurement of the offset angle of the motor encoder, the PLC controller sends an EXT operation instruction to the frequency converter, and the frequency converter performs the first stage of measurement of the offset angle of the motor encoder after receiving the EXT operation instruction to obtain a first offset angle; The first offset angle is recorded in the transmission control system to enable the PLC controller to control the motor to start and stop, reverse, and run at a constant speed set by the speed, so as to preliminarily position the motor encoder; The first stage of measurement of the offset angle of the motor encoder to obtain the first offset angle comprises: Triggering a low-speed measurement mode, in which the speed control amount in the EXT operation instruction is shielded, and a constant current is applied to the motor stator and excitation circuit to control the motor to rotate at a low speed, so as to measure the offset angle in the low-speed measurement mode; Triggering a high-speed measurement mode, in which, on the basis of the offset angle in the low-speed measurement mode, the motor is controlled to automatically accelerate to the motor base speed when the motor is forward and reverse, and the offset angle in the high-speed measurement mode is measured according to the angle deviation of the output voltage of the frequency converter as the first offset angle.

2. The method of claim 1, wherein, Before installing the motor encoder, the method further comprises fixing the rotating shaft.

3. The method of claim 1, wherein, After the PLC controller controls the motor to start and stop, reverse, and run at a constant speed set by the speed, the method further comprises: Correcting the coaxiality of the motor encoder and the motor rotor, and performing the second stage of measurement of the offset angle of the motor encoder to obtain a second offset angle; Recording the second offset angle in the transmission control system to finally position the motor encoder.

4. The method of claim 3, wherein, The correction of the coaxiality of the motor encoder and the motor rotor is ≤0.05 mm.

5. The method of claim 3, wherein, The second stage of measurement of the offset angle of the motor encoder to obtain the second offset angle comprises: Consecutively measuring the offset angle of the motor encoder twice to obtain two offset angle measurement values; If the deviation of the two offset angle measurement values is less than or equal to a preset difference value, the offset angle measurement value is determined as the second offset angle.

6. The method of claim 5, wherein, The preset difference value is 1°.

7. The method according to any one of claims 1 to 6, characterized in that, The motor comprises a synchronous motor in a rough rolling R1R2 rolling mill or a finishing rolling F1-F7 rolling mill.

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