A method for a permanent magnet motor to resist harmonics

Abstract

The present invention relates to a method for anti-harmonic of a permanent magnet motor, belonging to the field of harmonic processing. The method includes collecting the motor image of the permanent magnet motor; determining the motor position and the power supply position from the motor image, and determining a test stroke in response to the motor position; controlling a preset test device to place the permanent magnet motor into a preset detection station according to the test stroke, and determining a power supply stroke in response to the power supply position; controlling the preset test device to be connected to the input end and the output end of the permanent magnet motor respectively according to the power supply stroke, and identifying the motor model from the motor image; determining a test current in response to the motor model; controlling the preset test device to input the test current into the permanent magnet motor, and collecting the motor temperature of the permanent magnet motor; when the motor temperature is greater than a preset use threshold, controlling a preset control terminal to issue a harmonic alarm based on the motor temperature. This application has the effects of improving the working stability of the permanent magnet motor and being able to detect the failure of the permanent magnet motor in time.

Description

Technical Field

[0001] The present invention relates to the field of harmonic processing, and more particularly to a method for a permanent magnet motor to resist harmonics. Background Art

[0002] A permanent magnet motor is a motor that uses permanent magnets to generate a magnetic field.

[0003] In the prior art, permanent magnet motors are prone to generating harmonics during use. Harmonics can have an adverse impact on the performance, losses, and heating of permanent magnet motors. Therefore, when using a permanent magnet motor, it is necessary to ensure that the harmonics in the circuit are as low as possible. A permanent magnet motor contains many components, and when any component fails, it is easy to cause a high level of harmonics in the permanent magnet motor.

[0004] When the harmonics in the circuit where the permanent magnet motor is located are high, it is easy to cause abnormal heating of the permanent magnet motor and even damage to the motor. Summary of the Invention

[0005] In order to improve the working stability of a permanent magnet motor and be able to detect failures of the permanent magnet motor in a timely manner, the present invention provides a method for a permanent magnet motor to resist harmonics.

[0006] In a first aspect, the present invention provides a method for a permanent magnet motor to resist harmonics, adopting the following technical solution:

[0007] A method for a permanent magnet motor to resist harmonics includes:

[0008] Step 100: Collect an image of the permanent magnet motor.

[0009] Step 101: Determine the motor position and the power supply position from the motor image, and determine a test stroke in response to the motor position.

[0010] Step 102: Control a preset test device to place the permanent magnet motor into a preset detection station according to the test stroke, and determine a power supply stroke in response to the power supply position.

[0011] Step 103: Control the preset test device to connect to the input end and the output end of the permanent magnet motor according to the power supply stroke, and identify the motor model from the motor image.

[0012] Step 104: Determine a test current in response to the motor model.

[0013] Step 105: Control the preset test device to input the test current into the permanent magnet motor and collect the motor temperature of the permanent magnet motor.

[0014] Step 106: When the motor temperature is greater than a preset usage threshold, control a preset control terminal to issue a harmonic alarm based on the motor temperature.

[0015] By adopting the above technical solution, the type and power input terminal of the motor are identified by using image recognition technology, so as to automatically conduct a power-on test on the motor and monitor the heat generation situation of the motor in real time during power-on. Thus, when the harmonics in the motor are relatively high and cause abnormal heat generation, an alarm is timely sent through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor.

[0016] Optionally, it further includes:

[0017] Step 107: When the temperature of the motor is greater than a preset usage threshold, collect the magnetic field intensity of the permanent magnet motor;

[0018] Step 108: Determine the magnetic field distribution in response to the magnetic field intensity;

[0019] Step 109: Determine the strong magnetic position in response to the magnetic field distribution;

[0020] Step 110: Control a preset control terminal to issue a harmonic alarm based on the motor temperature and the strong magnetic position.

[0021] By adopting the above technical solution, when the harmonics in the motor are relatively high, the current in the motor is likely to be relatively large, resulting in a relatively large magnetic field intensity generated when the current flows through the motor. The magnetic field intensity emitted by the motor is detected in real time, so as to identify the position where the magnetic field of the motor is distorted and issue an alarm through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor.

[0022] Optionally, it further includes:

[0023] Step 111: When the strong magnetic position falls within a preset rotor interval, determine a reference current in response to the test current;

[0024] Step 112: Control a preset test device to input the reference current into the permanent magnet motor and update the magnetic field intensity;

[0025] Step 113: Determine the intensity drop in response to the magnetic field intensity, and determine the current drop in response to the detected current and the reference current;

[0026] Step 114: Determine the influence coefficient in response to the intensity drop and the current drop;

[0027] Step 115: Screen out the harmonic parts in response to the influence coefficient and the strong magnetic position;

[0028] Step 116: Control a preset control terminal to issue a part alarm based on the harmonic parts.

[0029] By adopting the above technical solution, when a component of the motor fails, it is likely to cause the harmonics in the motor to increase. The harmonics generated by failures in different parts vary with the current. By changing the magnitude of the current input to the motor to test the change in the magnetic field emitted by the motor, the change in harmonics is then reflected through the change in the magnetic field, and further, the location of the failure in the motor is determined through the change in harmonics, and an alarm is sent through the control terminal in a timely manner.

[0030] Optionally, it further includes a rotor detection method, and the rotor detection method includes:

[0031] Step 200: When the strong magnetic position falls within a preset rotor interval, determine the impact force in response to the motor model;

[0032] Step 201: Determine the impact stroke in response to the impact force and the strong magnetic position;

[0033] Step 202: Determine the update time in response to the impact stroke;

[0034] Step 203: Control a preset test device to throw out the permanent magnet motor according to the impact stroke, and update the magnetic field strength after the update time;

[0035] Step 204: Determine the impact drop in response to the magnetic field strength;

[0036] Step 205: Determine the impact coefficient in response to the impact drop;

[0037] Step 206: When the impact coefficient is higher than a preset coefficient threshold, determine the offset distance in response to the impact coefficient;

[0038] Step 207: Based on the offset distance, control a preset control terminal to send an offset alarm.

[0039] By adopting the above technical solution, when the rotor in the motor is eccentric, it is likely to cause uneven air gaps between the rotor and the stator, thereby causing the harmonics of the motor to increase. The motor is swung by the test device so that the components in the motor offset according to inertia and the magnetic field is detected in real time, so as to judge the eccentricity of the rotor of the motor when the magnetic field changes after the motor is swung, and an alarm is sent through the control terminal in a timely manner.

[0040] Optionally, the rotor detection method further includes:

[0041] Step 208: When the impact coefficient is higher than a preset coefficient threshold, determine the offset direction in response to the strong magnetic position, the impact drop, and the intensity drop;

[0042] Step 209: Determine the correction intensity in response to the offset direction, the offset distance, and the magnetic field strength;

[0043] Step 210: Determine the test intensity in response to the correction intensity, influence coefficient, and test current;

[0044] Step 211: Determine the test distribution in response to the test intensity;

[0045] Step 212: Determine the strong magnetic volume in response to the test distribution;

[0046] Step 213: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the demagnetized position in response to the test distribution;

[0047] Step 214: Control a preset control terminal to issue a demagnetization alarm based on the demagnetized position.

[0048] By adopting the above technical solution, the detected magnetic field emitted by the motor is corrected according to the component failure condition in the motor and the offset condition of the rotor, so as to obtain the magnetic field emitted by the stator of the motor, and further identify the position where the permanent magnet is defective from the magnetic field emitted by the stator, and timely issue an alarm through the control terminal.

[0049] Optionally, the rotor detection method further includes:

[0050] Step 215: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the magnetic compensation stroke in response to the demagnetized position;

[0051] Step 216: Control a preset magnetic compensation device to move to the demagnetized position according to the magnetic compensation stroke, and determine the demagnetized volume in response to the demagnetized position;

[0052] Step 217: Determine the magnetic compensation intensity in response to the demagnetized volume;

[0053] Step 218: Control a preset magnetic compensation device to emit a magnetic field according to the magnetic compensation intensity, and control a preset test device to input a permanent magnet motor according to the test current to update the motor temperature;

[0054] Step 219: When the motor temperature is not greater than a preset rotor threshold, control a preset control terminal to issue a magnetic compensation suggestion based on the demagnetized position and demagnetized volume.

[0055] By adopting the above technical solution, when a permanent magnet in the motor is defective, the magnetic force at the defective position is supplemented outside the motor through a magnetic compensation device, so as to detect the heat generation condition of the motor after the magnetic force is supplemented to judge the effect of the magnetic force supplement, and further remind the staff to replace or supplement the permanent magnet through the control terminal when the effect of the magnetic force supplement is good.

[0056] Optionally, the method for determining the rotor threshold includes:

[0057] Step 220: When the volume of the strong magnetic field is lower than a preset strong magnetic threshold, determine the cooling rate in response to the motor temperature;

[0058] Step 221: Determine the temperature difference in response to the motor temperature and the usage threshold;

[0059] Step 222: Determine the correction threshold in response to the motor temperature, the temperature difference, and the cooling rate;

[0060] Step 223: Determine the rotor threshold in response to the magnetic flux replenishment intensity and the correction threshold.

[0061] By adopting the above technical solution, according to the temperature change of the motor, estimate the temperature value of the motor when it is energized after the magnetic force is supplemented by the magnetic flux replenishment device, and estimate the maximum temperature value that the motor can easily reach during normal operation according to the temperature value of the motor when it is energized after the magnetic force is supplemented, so as to evaluate the harmonic situation of the motor.

[0062] Optionally, it further includes a magnetic flux replenishment method, and the magnetic flux replenishment method includes:

[0063] Step 300: When the motor temperature is not greater than the preset rotor threshold, determine the magnetic flux replenishment quantity in response to the magnetic flux replenishment intensity;

[0064] Step 301: Determine the demagnetized area in response to the demagnetized position;

[0065] Step 302: Determine the single-layer quantity in response to the demagnetized area;

[0066] Step 303: Determine the magnetic addition stroke in response to the magnetic flux replenishment quantity, the single-layer quantity, and the demagnetized area;

[0067] Step 304: Control a preset test device to adhere a preset magnetic block to the demagnetized area according to the magnetic addition stroke.

[0068] By adopting the above technical solution, when the magnetic flux replenishment effect of the magnetic flux replenishment device is good, arrange the pre-prepared magnetic blocks at the corresponding positions on the motor housing where the permanent magnet is defective through the test device, so as to supplement the magnetic force of the permanent magnet inside the motor outside the motor through the magnetic blocks, and reduce the generation of harmonics in the motor.

[0069] Optionally, the magnetic flux replenishment method further includes:

[0070] Step 305: When the magnetic flux replenishment quantity is not less than the single-layer quantity, determine the barrier thickness in response to the magnetic flux replenishment quantity;

[0071] Step 306: Determine the permanent magnet boundary in response to the demagnetized area and the test distribution;

[0072] Step 307: Determine the injection stroke in response to the barrier thickness and the permanent magnet boundary;

[0073] Step 308: Control the preset glue injection device to inject glue on the permanent magnet boundary according to the injection stroke.

[0074] By adopting the above technical solution, when there are many magnetic blocks to be supplemented, the distance between the permanent magnet and the magnetic blocks is too close, which easily causes the magnetic blocks to be attracted or repelled by the permanent magnet, resulting in the situation that the magnetic blocks shift on the motor housing. The glue injection device injects glue on the motor housing to block the magnetic blocks and the permanent magnet, thereby reducing the situation of magnetic block shift.

[0075] Optionally, it further includes an inverter selection method, and the inverter selection method includes:

[0076] Step 400: When the motor temperature is greater than the preset usage threshold, determine the harmonic amplitude in response to the motor temperature;

[0077] Step 401: Determine the inverter voltage drop in response to the harmonic amplitude;

[0078] Step 402: Determine the inverter number in response to the motor model and the inverter voltage drop;

[0079] Step 403: Based on the inverter number, control the preset control terminal to display anti-harmonic suggestions.

[0080] By adopting the above technical solution, when the harmonics generated by the motor are relatively high, it easily causes the voltage in the circuit to be unstable, resulting in damage to other components in the circuit where the motor is located. Select a suitable inverter according to the harmonic situation and working conditions of the motor to protect the circuit.

[0081] In summary, the present application includes at least one of the following beneficial technical effects:

[0082] 1. Adopt image recognition technology to identify the model and power input end of the motor, thereby automatically conduct a power-on test on the motor and real-time monitor the heat generation situation of the motor during power-on. When the harmonics in the motor are relatively high and cause abnormal heat generation, an alarm is timely issued through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor;

[0083] 2. When the harmonics in the motor are relatively high, the current in the motor is likely to be large, resulting in a relatively large magnetic field intensity generated when the current flows through the motor. Real-time detect the magnetic field intensity emitted by the motor to identify the position where the magnetic field of the motor is distorted and issue an alarm through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor;

[0084] 3. When components of the motor fail, it is easy to cause an increase in harmonics in the motor. The harmonics generated by faults in different parts vary with the current. By changing the magnitude of the current input to the motor to test the change in the magnetic field emitted by the motor, the change in harmonics is then reflected through the change in the magnetic field, and further, the location of the fault in the motor is determined through the change in harmonics, and an alarm is sent through the control terminal in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is the flow chart of a method for a permanent magnet motor to resist harmonics Figure 1 ;

[0086] Figure 2 is the flow chart of a method for a permanent magnet motor to resist harmonics Figure 2 ;

[0087] Figure 3 is the flow chart of a method for a permanent magnet motor to resist harmonics Figure 3 ;

[0088] Figure 4 is the flow chart of a rotor detection method Figure 1 ;

[0089] Figure 5 is the flow chart of a rotor detection method Figure 2 ;

[0090] Figure 6 is the flow chart of a rotor detection method Figure 3 ;

[0091] Figure 7 is the flow chart of a method for determining rotor threshold;

[0092] Figure 8 is the flow chart of a magnetic flux supplement method Figure 1 ;

[0093] Figure 9 is the flow chart of a magnetic flux supplement method Figure 2 ;

[0094] Figure 10 is the flow chart of an inverter selection method. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0095] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0096] Refer to Figure 1 , this application embodiment discloses a method for a permanent magnet motor to resist harmonics, including:

[0097] Step 100: Collect the motor image of the permanent magnet motor.

[0098] The motor image refers to the picture of the permanent magnet motor. The motor image can be collected by a fixed camera. The method for collecting the motor image is selected by the staff according to the actual situation and will not be elaborated here.

[0099] Step 101: Determine the motor position and the power supply position from the motor image, and determine the test travel in response to the motor position.

[0100] The motor position refers to the position information where the permanent magnet motor is located. The power supply position refers to the port position information for power supply input and output on the permanent magnet motor. Both the motor position and the power supply position can be determined by image recognition technology. The recognition methods for the motor position and the power supply position are common knowledge for those skilled in the art and will not be elaborated here.

[0101] The test device refers to the equipment used to grab the permanent magnet motor and energize the permanent magnet motor. Generally, a robotic arm is used for the test device. The detection station refers to the area for detecting the harmonic condition of the motor. Both the test device and the detection station are selected by the staff according to the actual situation and will not be elaborated here.

[0102] The test travel refers to the route for the test device to grab the permanent magnet motor to the center of the detection station. After the test device grabs the permanent magnet motor to the center of the test station, the drive shaft of the permanent magnet motor is kept perpendicular to the plane of the test station. The method for determining the test travel is common knowledge for those skilled in the art and will not be elaborated here.

[0103] Step 102: Control the preset test device to place the permanent magnet motor into the preset detection station according to the test travel, and determine the power supply travel in response to the power supply position.

[0104] The power supply travel refers to the route for the test device to energize the permanent magnet motor, that is, the route for the test device to connect the power supply line to the power supply position. The method for determining the power supply travel is common knowledge for those skilled in the art and will not be elaborated here.

[0105] Step 103: Control the preset test device to connect to the input end and the output end of the permanent magnet motor respectively according to the power supply travel, and identify the motor model from the motor image.

[0106] The motor model refers to the number used to distinguish the permanent magnet motor. The working current, working voltage, and driving force of permanent magnet motors with different motor models are different. The motor model can be determined by image recognition technology. The method for determining the motor model is common knowledge for those skilled in the art and will not be elaborated here.

[0107] Step 104: Determine the test current in response to the motor model.

[0108] The test current refers to the operating current of the permanent magnet motor. The test current can be obtained by querying the current data table, which is a data table recording different motor models and their corresponding test currents.

[0109] Step 105: Control the preset test device to input the test current into the permanent magnet motor and collect the motor temperature of the permanent magnet motor.

[0110] The motor temperature refers to the real-time temperature value of the permanent magnet motor. The motor temperature can be collected non-contact by an infrared sensor set at the detection station. The collection method of the motor temperature is selected by the staff according to the actual situation and will not be elaborated here.

[0111] Step 106: When the motor temperature is greater than the preset usage threshold, control the preset control terminal to issue a harmonic alarm based on the motor temperature.

[0112] The control terminal refers to a device used to display the harmonic situation of the permanent magnet motor to the staff. The control terminal is selected by the staff according to the actual situation and will not be elaborated here.

[0113] The usage threshold refers to the maximum temperature value that the motor can emit during normal use. The usage threshold is selected by the staff according to the actual situation and will not be elaborated here. The motor temperature being greater than the usage threshold means that the temperature during the motor's operation is too high, that is, the harmonics in the motor are too high. At this time, an alarm needs to be issued in time through the control terminal.

[0114] Adopt image recognition technology to identify the motor model and the power input terminal, so as to automatically conduct a power-on test on the motor and real-time monitor the heat generation situation of the motor during power-on. Thus, when the harmonics in the motor are relatively high and cause abnormal heat generation, an alarm is issued in time through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor.

[0115] Refer to Figure 2 A method for a permanent magnet motor to resist harmonics further includes:

[0116] Step 107: When the motor temperature is greater than the preset usage threshold, collect the magnetic field intensity of the permanent magnet motor.

[0117] The magnetic field intensity refers to the magnetic field intensity value at each point during the operation of the permanent magnet motor. The magnetic field intensity can be collected by a plurality of Hall sensors fixed inside the detection station and evenly arranged in a circle with the center of the plane of the detection station as the center and evenly arranged in a direction perpendicular to the plane of the detection station. The collection method of the magnetic field intensity is selected by the staff according to the actual situation and will not be elaborated here.

[0118] Step 108: Determine the magnetic field distribution in response to the magnetic field intensity.

[0119] The magnetic field distribution refers to the distribution map of the magnetic field in space when the permanent magnet motor is operating. The method for determining the magnetic field distribution is common knowledge to those skilled in the art and will not be elaborated here.

[0120] Step 109: Determine the strong magnetic position in response to the magnetic field distribution.

[0121] The strong magnetic position refers to the position point with the highest magnetic field intensity in the magnetic field distribution. The method for determining the strong magnetic position is common knowledge to those skilled in the art and will not be elaborated here.

[0122] Step 110: Control a preset control terminal to issue a harmonic alarm based on the motor temperature and the strong magnetic position.

[0123] When the harmonics in the motor are relatively high, the current in the motor is likely to be relatively large, which may lead to a relatively large magnetic field intensity generated when the current flows through the motor. By detecting the magnetic field intensity emitted by the motor in real time, the position where the magnetic field of the motor is distorted can be identified, and an alarm can be issued through the control terminal, reducing the occurrence of faults in the permanent magnet motor and improving the working stability of the permanent magnet motor.

[0124] Refer to Figure 3 , a method for a permanent magnet motor to resist harmonics, further comprising:

[0125] Step 111: When the strong magnetic position falls within a preset rotor interval, determine a reference current in response to the test current.

[0126] The rotor interval refers to the position range of the rotor in the permanent magnet motor. The rotor interval is selected by the staff according to the actual situation and will not be elaborated here. The strong magnetic position falling within the rotor interval represents a distorted magnetic field on the rotor, that is, a fault in the components on the rotor leads to an increase in harmonics. The reference current refers to the current when the permanent magnet motor is energized again through a test device. Generally, half of the test current is used as the reference current. The method for determining the reference current is selected by the staff according to the actual situation and will not be elaborated here.

[0127] Step 112: Control a preset test device to input the reference current into the permanent magnet motor and update the magnetic field intensity.

[0128] By adjusting the current input into the permanent magnet motor, the magnitude of the current flowing through the rotor can be adjusted, thereby obtaining the magnetic field conditions of the motor at different currents.

[0129] Step 113: Determine the intensity drop in response to the magnetic field intensity, and determine the current drop in response to the detected current and the reference current.

[0130] The intensity drop refers to the maximum value of the change in the magnetic field intensity, that is, the difference between the maximum magnetic field intensities of the permanent magnet motor under the test current and the reference current respectively. The method for determining the intensity drop is common knowledge to those skilled in the art and will not be elaborated here.

[0131] Step 114: Determine the influence coefficient in response to the intensity drop and current drop.

[0132] The influence coefficient refers to a value used to show the degree of influence of current change on magnetic field intensity change. Generally, the quotient of the intensity drop and current drop is used as the influence coefficient. The method for determining the influence coefficient is common knowledge for those skilled in the art and will not be elaborated here.

[0133] Step 115: Screen out the harmonic parts in response to the influence coefficient and the strong magnetic position.

[0134] The harmonic part refers to the position information of the component on the rotor that causes harmonics due to a fault. A permanent magnet motor includes a stator and a rotor. The stator includes permanent magnets, and the rotor includes components such as windings, brushes, and iron cores. The current only flows through the rotor. When the current input to the motor changes, only the magnetic field intensity emitted by the rotor changes. When faults occur in components such as windings, brushes, and iron cores, the variation of the harmonics generated varies with the magnitude of the current. The influence coefficient and its corresponding harmonic components can be queried from the harmonic data table, and then the harmonic parts where faults occur on the motor can be determined by combining the harmonic components and the strong magnetic position. The harmonic data table refers to a table that records different influence coefficients and their corresponding harmonic components, and only the minimum influence coefficient that can be caused by the harmonic components is recorded in the harmonic data table.

[0135] Step 116: Based on the harmonic part, control a preset control terminal to issue a part alarm.

[0136] When a component of the motor fails, it is likely to cause an increase in harmonics in the motor. The harmonics generated by faults in different parts vary with the change of current. By changing the magnitude of the current input to the motor to test the change of the magnetic field emitted by the motor, the change of harmonics can be reflected through the change of the magnetic field, and then the part where a fault occurs in the motor can be judged through the change of harmonics, and an alarm can be issued in a timely manner through the control terminal.

[0137] Refer to Figure 4 , the rotor detection method includes:

[0138] Step 200: When the strong magnetic position falls into a preset rotor interval, determine the impact force in response to the motor model.

[0139] The impact force refers to the force that the testing device drives the motor to the center of the detection station. The rotor weight corresponding to the motor model can be queried from the rotor data table, and then an appropriate impact force can be selected according to the rotor weight. Generally, twice the rotor weight is used as the impact force. The rotor weight refers to the weight value of the rotor of the motor. The rotor data table refers to a table that records different motor models and their corresponding rotor weights. The impact force is selected by the staff according to the actual situation and will not be elaborated here.

[0140] Step 201: Determine the impact stroke in response to the impact force and the strong magnetic position.

[0141] The impact stroke refers to the route where the test device moves the permanent magnet motor to the edge of the detection station according to the strong magnetic position and then moves it to the center of the detection station with the impact force. When the test device moves the permanent magnet motor to the edge of the detection station, the relative relationship between the strong magnetic position and the center position of the permanent magnet motor is first determined. For example, when the strong magnetic position is located on the east side of the center position of the permanent magnet motor, the test device is controlled to move the permanent magnet motor to the east edge of the detection station, and then the test device is controlled to move the permanent magnet motor westward to the center of the detection station. The method for determining the impact stroke is common knowledge for those skilled in the art and will not be elaborated here.

[0142] Step 202: Determine the update time in response to the impact stroke.

[0143] The update time refers to the duration of the impact stroke. The method for determining the update time is common knowledge for those skilled in the art and will not be elaborated here.

[0144] Step 203: Control the preset test device to throw out the permanent magnet motor according to the impact stroke and update the magnetic field strength after the update time.

[0145] Control the test device to quickly move the permanent magnet motor, so that when the permanent magnet motor reaches the center of the detection station and stops moving under the control of the test device, the rotor in the permanent magnet motor is deflected due to inertia, and thus the deflection of the rotor in the motor can be judged through the magnetic field.

[0146] Step 204: Determine the impact drop in response to the magnetic field strength.

[0147] The impact drop refers to the difference in magnetic field strength before and after the permanent magnet motor moves according to the impact stroke. The method for determining the impact drop is common knowledge for those skilled in the art and will not be elaborated here.

[0148] Step 205: Determine the impact coefficient in response to the impact drop.

[0149] The impact coefficient refers to a value used to show the deflection of the rotor. Generally, the quotient of the impact drop and the magnetic field strength is used as the impact coefficient. The method for determining the impact coefficient is common knowledge for those skilled in the art and will not be elaborated here.

[0150] Step 206: When the impact coefficient is higher than the preset coefficient threshold, determine the deflection distance in response to the impact coefficient.

[0151] The coefficient threshold refers to the maximum impact coefficient value that allows the rotor of the electron to deviate. The coefficient threshold is selected by the staff according to the actual situation and will not be elaborated here. An impact coefficient higher than the coefficient threshold indicates that the rotor offset of the permanent magnet motor is too severe, which easily leads to rotor eccentricity and thus an increase in harmonics. The offset distance refers to the maximum distance that the rotor of the motor can offset. The offset distance corresponding to the impact coefficient can be queried from the coefficient data table. The coefficient data table refers to the data table that records different impact coefficients and their corresponding offset distances. Each motor model has its corresponding coefficient data table. After the motor model is determined, the system automatically retrieves its corresponding coefficient data table.

[0152] Step 207: Based on the offset distance, control a preset control terminal to issue an offset alarm.

[0153] When the rotor in the motor is eccentric, it is easy to cause uneven air gaps between the rotor and the stator, resulting in an increase in the harmonics of the motor. The motor is swung by a testing device so that the components in the motor offset according to inertia and the magnetic field is detected in real time. Thus, when the magnetic field changes after the motor is swung, it is determined that the rotor of the motor is eccentric, and then an alarm is promptly issued through the control terminal.

[0154] Refer to Figure 5 , the rotor detection method further includes:

[0155] Step 208: When the impact coefficient is higher than a preset coefficient threshold, determine the offset direction in response to the strong magnetic position, impact drop, and intensity drop.

[0156] The offset direction refers to the direction in which the rotor deviates. The offset direction can be determined according to the change in the magnetic field strength. The method for determining the offset direction is common knowledge in the art and will not be elaborated here.

[0157] Step 209: Determine the correction intensity in response to the offset direction, offset distance, and magnetic field strength.

[0158] The correction intensity refers to the magnetic field strength value when the rotor is not eccentric, that is, the magnetic field strength value after the rotor offsets according to the offset direction and offset distance. The method for determining the correction intensity is common knowledge in the art and will not be elaborated here.

[0159] Step 210: Determine the test intensity in response to the correction intensity, influence coefficient, and test current.

[0160] The test intensity is the magnetic field strength emitted by the permanent magnet on the stator, that is, the intensity value obtained by subtracting the magnetic field strength emitted by the test current from the correction intensity. The method for determining the test intensity is common knowledge in the art and will not be elaborated here.

[0161] Step 211: Determine the test distribution in response to the test intensity.

[0162] The test distribution refers to the distribution map of the magnetic field of the permanent magnet in space. The method for determining the magnetic field distribution is common knowledge to those skilled in the art and will not be elaborated here.

[0163] Step 212: Determine the strong magnetic volume in response to the test distribution.

[0164] The strong magnetic volume refers to the volume value of the region where the magnetic field strength is higher than the preset magnet threshold. The magnet threshold refers to the magnetic field strength value on the surface of the permanent magnet, and the magnet threshold is selected by the staff according to the actual situation. The method for determining the strong magnetic volume is common knowledge to those skilled in the art and will not be elaborated here.

[0165] Step 213: When the strong magnetic volume is lower than the preset strong magnetic threshold, determine the demagnetized position in response to the test distribution.

[0166] The strong magnetic threshold refers to the total volume of the permanent magnets on the motor, and the strong magnetic threshold is selected by the staff according to the actual situation and will not be elaborated here. The strong magnetic volume being lower than the strong magnetic threshold means that the volume of the permanent magnets in the motor is too small, that is, the permanent magnets are defective. The demagnetized position is the position information where the permanent magnets are defective. First, the distribution area of the permanent magnets can be retrieved in advance, then the electromagnetic intensity values of each point within the distribution area are extracted from the test distribution, and finally, the difference between the electromagnetic intensity value and the magnet threshold is calculated and the position with the largest difference is selected as the demagnetized position. The distribution area refers to the range of the permanent magnets expected to be installed in the motor, and the distribution area can be input by the staff in advance. The method for determining the demagnetized position is common knowledge to those skilled in the art and will not be elaborated here.

[0167] Step 214: Control a preset control terminal to issue a demagnetization alarm based on the demagnetized position.

[0168] Modify the detected magnetic field emitted by the motor according to the component failure situation in the motor and the offset situation of the rotor, so as to obtain the magnetic field emitted by the stator of the motor, and then identify the position where the permanent magnets are defective from the magnetic field emitted by the stator in time to issue an alarm through the control terminal.

[0169] Refer to Figure 6 , the rotor detection method further includes:

[0170] Step 215: When the strong magnetic volume is lower than the preset strong magnetic threshold, determine the magnetic compensation stroke in response to the demagnetized position.

[0171] The magnetic compensation device refers to an electromagnet device used to supplement the magnetic force of the permanent magnet. The magnetic compensation device is selected by the staff according to the actual situation and will not be elaborated here. The magnetic compensation stroke refers to the route for the magnetic compensation device to move to the position on the motor housing surface closest to the demagnetized position. The method for determining the magnetic compensation stroke is common knowledge to those skilled in the art and will not be elaborated here.

[0172] Step 216: Control a preset magnetic flux compensation device to move to the demagnetized position according to the magnetic flux compensation stroke, and determine the demagnetized volume in response to the demagnetized position.

[0173] The demagnetized volume refers to the volume value of the permanent magnet missing at the demagnetized position. The actual distribution of the permanent magnet can be extracted from the test distribution and compared with the distribution area to obtain the demagnetized volume. The method for determining the demagnetized volume is common knowledge to those skilled in the art and will not be elaborated here.

[0174] Step 217: Determine the magnetic flux compensation intensity in response to the demagnetized volume.

[0175] The magnetic flux compensation intensity refers to the magnetic intensity contained in the permanent magnet with the demagnetized volume. The method for determining the demagnetized intensity is common knowledge to those skilled in the art and will not be elaborated here.

[0176] Step 218: Control the preset magnetic flux compensation device to emit a magnetic field according to the magnetic flux compensation intensity, and control the preset test device to input a test current into the permanent magnet motor to update the motor temperature.

[0177] The magnetic flux of the motor missing is supplemented outside the motor through the magnetic flux compensation device, so as to re-energize the motor to test the harmonic condition of the motor, and further verify the influence degree of the permanent magnet defect on the magnitude of the internal harmonics of the motor.

[0178] Step 219: When the motor temperature is not greater than a preset rotor threshold, control a preset control terminal to issue a magnetic flux compensation suggestion based on the demagnetized position and the demagnetized volume.

[0179] The rotor threshold refers to the maximum temperature value that the motor can emit during normal use. The rotor threshold is selected by the staff according to the actual situation and will not be elaborated here. The motor temperature not being greater than the rotor threshold represents that the temperature during the operation of the motor is normal, that is, the effect of the magnetic flux compensation device is good. At this time, it is necessary to notify the staff through the control terminal to repair the permanent magnet in the motor in time.

[0180] When the permanent magnet in the motor is defective, the magnetic force at the defective position is supplemented outside the motor through the magnetic flux compensation device, so as to detect the heating condition of the motor after the magnetic force is supplemented to judge the effect of the supplemented magnetic force, and further remind the staff to replace or supplement the permanent magnet through the control terminal when the heating condition of the motor decreases.

[0181] Refer to Figure 7 , the method for determining the rotor threshold includes:

[0182] Step 220: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the cooling rate in response to the motor temperature.

[0183] The temperature drop rate refers to the temperature value that the motor drops per unit time. The method for determining the temperature drop rate is common knowledge for those skilled in the art and will not be elaborated here.

[0184] Step 221: Determine the temperature difference in response to the motor temperature and the usage threshold.

[0185] The temperature difference is the difference between the motor temperature and the usage threshold, which can be determined by calculating the difference between the motor temperature and the usage threshold.

[0186] Step 222: Determine the correction threshold in response to the motor temperature, the temperature difference, and the temperature drop rate.

[0187] The correction threshold is the temperature value used to determine whether the heat generation of the motor is abnormal. Generally, the temperature value of the motor when it cools down to the temperature at which the magnet supplement device supplements the magnet and then the motor is powered on again according to the temperature drop rate is used as the correction threshold. When the correction threshold is lower than the usage threshold, the usage threshold is used as the correction threshold.

[0188] Step 223: Determine the rotor threshold in response to the magnet supplement intensity and the correction threshold.

[0189] The rotor threshold is the maximum operating temperature value of the motor when the magnetic field of the permanent magnet on the stator is uniform. First, the harmonic size caused by the missing permanent magnet can be estimated through the magnet supplement intensity, then the additional heat generation situation of the motor can be estimated according to the harmonic size, and finally, the difference between the correction threshold and the heat generation situation is calculated as the rotor threshold.

[0190] Estimate the temperature value of the motor when it is powered on after supplementing magnetic force through the magnet supplement device according to the temperature change situation of the motor, and estimate the maximum temperature value that the motor can easily reach during normal operation according to the temperature value of the motor when it is powered on after supplementing magnetic force, so as to evaluate the harmonic situation of the motor.

[0191] Refer to Figure 8 , the magnet supplement method includes:

[0192] Step 300: When the motor temperature is not greater than the preset rotor threshold, determine the magnet supplement quantity in response to the magnet supplement intensity.

[0193] The magnetic block refers to the small particles of permanent magnet prepared in advance. The shape and the contained magnetic force of each magnetic block are the same. The magnetic blocks are selected by the staff according to the actual situation and will not be elaborated here. The magnet supplement quantity is the minimum number of magnetic blocks required to reach the magnetic force of the magnet supplement intensity. The method for determining the magnet supplement quantity is common knowledge for those skilled in the art and will not be elaborated here.

[0194] Step 301: Determine the magnet missing area in response to the magnet missing position.

[0195] The demagnetized area refers to the area on the motor housing that maps the range where the permanent magnet is defective. The method for determining the demagnetized area is common knowledge for those skilled in the art and will not be elaborated here.

[0196] Step 302: Determine the number of single layers in response to the demagnetized area.

[0197] The number of single layers refers to the maximum number of magnetic blocks that can be laid in a single layer within the demagnetized area. The method for determining the number of single layers is common knowledge for those skilled in the art and will not be elaborated here.

[0198] Step 303: Determine the magnet-adding travel in response to the number of magnetic blocks to be added, the number of single layers, and the demagnetized area.

[0199] The glue injection device refers to the equipment used to inject glue onto the motor housing. The glue injection device is selected by the staff according to the actual situation and will not be elaborated here. The magnet-adding travel refers to the route for fixing the magnetic blocks of the number of magnetic blocks to be added to the demagnetized area through the testing device. Among them, the magnetic blocks exceeding the number of single layers are adhered to the magnetic blocks of the previous layer to reduce the situation where the magnetic blocks exceed the demagnetized area. Among them, the magnetic blocks are adhered and fixed to the motor housing. Generally, the glue injection device is used to pre-inject glue at the corresponding position and then the testing device is used to fix the magnetic blocks on the glue. The method for determining the magnet-adding travel is common knowledge for those skilled in the art and will not be elaborated here.

[0200] Step 304: Control the preset testing device to adhere the preset magnetic blocks to the demagnetized area according to the magnet-adding travel.

[0201] When the magnetic block adding effect of the magnetic block adding device is good, the magnetic blocks prepared in advance are arranged at the corresponding positions on the motor housing where the permanent magnet is defective through the testing device, so as to supplement the magnetic force of the permanent magnet in the motor outside the motor through the magnetic blocks and reduce the generation of harmonics in the motor.

[0202] Refer to Figure 9 , the magnetic block adding method further includes:

[0203] Step 305: When the number of magnetic blocks to be added is not less than the number of single layers, determine the barrier thickness in response to the number of magnetic blocks to be added.

[0204] The number of magnetic blocks to be added not less than the number of single layers means that at least one layer of magnetic blocks is in contact with the edge of the demagnetized area, and the edge of the demagnetized area is in contact with the mapped position of the installation position of the permanent magnet on the motor housing. At this time, the magnetic blocks are too close to the permanent magnet. The barrier thickness is the minimum thickness value for blocking the permanent magnet with glue to reduce the acting force of the permanent magnet on the magnetic blocks. The barrier thickness can be obtained by querying from the thickness relationship table. The thickness relationship table refers to the data table recording different numbers of magnetic blocks to be added and their corresponding barrier thicknesses.

[0205] Step 306: Determine the permanent magnet boundary in response to the demagnetized area and the test distribution.

[0206] The permanent magnet boundary is the boundary line where the edge of the magnet-deficient region contacts the mapped position of the installation position of the permanent magnet on the motor housing. The method for determining the permanent magnet boundary is common knowledge to those skilled in the art and will not be elaborated here.

[0207] Step 307: Determine the injection stroke in response to the barrier thickness and the permanent magnet boundary.

[0208] The injection stroke is the route for injecting glue with a barrier thickness between the magnetic block and the motor housing through the injection device. The method for determining the injection stroke is common knowledge to those skilled in the art and will not be elaborated here.

[0209] Step 308: Control the preset glue injection device to inject glue along the injection stroke on the permanent magnet boundary.

[0210] When there are many magnetic blocks to be supplemented, the distance between the permanent magnet and the magnetic block is too close, which easily causes the magnetic block to be attracted or repelled by the permanent magnet, resulting in the magnetic block shifting on the motor housing. Glue is injected on the motor housing through the glue injection device to block the magnetic block and the permanent magnet, thereby reducing the situation of magnetic block shifting.

[0211] Refer to Figure 10 , the inverter selection method includes:

[0212] Step 400: When the motor temperature is greater than the preset usage threshold, determine the harmonic amplitude in response to the motor temperature.

[0213] The harmonic amplitude refers to the magnitude of the harmonic. The harmonic amplitude corresponding to the motor temperature can be queried from the harmonic correspondence table. The harmonic correspondence table is a data table recording the harmonic amplitudes corresponding to different motor temperatures, and each motor model has its corresponding harmonic correspondence table.

[0214] Step 401: Determine the inverter voltage drop in response to the harmonic amplitude.

[0215] An inverter is a device used to reduce the harm of harmonics to the circuit, generally using inverter diodes. The inverter is selected by the staff according to the actual situation and will not be elaborated here. The inverter voltage drop is the voltage drop parameter of the inverter. The method for determining the inverter voltage drop is common knowledge to those skilled in the art and will not be elaborated here.

[0216] Step 402: Determine the inverter number in response to the motor model and the inverter voltage drop.

[0217] The inverter number is the number used to distinguish inverters. Generally, the model of the inverter is used as the inverter number. The inverter number corresponding to the motor model and the inverter voltage drop can be queried from the inverter database. The inverter database is a data table recording the inverter numbers of inverters that can be applied to the permanent magnet motor circuit of the motor model and whose voltage drop is not lower than the inverter voltage drop.

[0218] Step 403: Based on the inversion number, control a preset control terminal to display anti-harmonic suggestions.

[0219] When the harmonics generated by the motor are relatively high, it is likely to cause voltage instability in the circuit, thereby resulting in damage to other components in the circuit where the motor is located. Select a suitable inverter according to the harmonic conditions and operating conditions of the motor to protect the circuit.

[0220] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A method for anti - harmonic of a permanent - magnet motor, characterized in that, Including: Step 100: Collect the motor image of the permanent magnet motor; Step 101: Determine the motor position and the power supply position from the motor image, and determine the test stroke in response to the motor position; Step 102: Control the preset test device to place the permanent magnet motor into the preset detection station according to the test stroke, and determine the power supply stroke in response to the power supply position; Step 103: Control the preset test device to connect to the input end and the output end of the permanent magnet motor respectively according to the power supply stroke, and identify the motor model from the motor image; Step 104: Determine the test current in response to the motor model; Step 105: Control the preset test device to input the permanent magnet motor according to the test current, and collect the motor temperature of the permanent magnet motor; Step 106: When the motor temperature is greater than the preset usage threshold, control the preset control terminal to issue a harmonic alarm based on the motor temperature; Also including: Step 107: When the motor temperature is greater than the preset usage threshold, collect the magnetic field intensity of the permanent magnet motor; Step 108: Determine the magnetic field distribution in response to the magnetic field intensity; Step 109: Determine the strong magnetic position in response to the magnetic field distribution; Step 110: Control the preset control terminal to issue a harmonic alarm based on the motor temperature and the strong magnetic position; Also including: Step 111: When the strong magnetic position falls into the preset rotor interval, determine the comparison current in response to the test current; Step 112: Control the preset test device to input the permanent magnet motor according to the comparison current, and update the magnetic field intensity; Step 113: Determine the intensity drop in response to the magnetic field intensity, and determine the current drop in response to the detection current and the comparison current. The intensity drop refers to the maximum value of the change in the magnetic field intensity; Step 114: Determine the influence coefficient in response to the intensity drop and the current drop. The influence coefficient is a value used to show the influence degree of the current change on the magnetic field intensity change, and the quotient of the intensity drop and the current drop is used as the influence coefficient; Step 115: Screen out the harmonic parts in response to the influence coefficient and the strong magnetic position. The harmonic parts refer to the component position information on the rotor where a fault occurs and causes harmonics; Step 116: Control the preset control terminal to issue a part alarm based on the harmonic parts; 2. A method for anti - harmonic of a permanent - magnet motor according to claim 1, characterized in that, Also including a rotor detection method, and the rotor detection method includes: Step 200: When the strong magnetic position falls into the preset rotor interval, determine the impact force in response to the motor model; Step 201: Determine the impact stroke in response to the impact force and the strong magnetic position; Step 202: Determine the update time in response to the impact stroke; Step 203: Control the preset test device to throw out the permanent magnet motor according to the impact stroke, and update the magnetic field intensity after the update time; Step 204: Determine the impact drop in response to the magnetic field intensity. The impact drop refers to the difference in the magnetic field intensity before and after the permanent magnet motor moves according to the impact stroke; Step 205: Determine the impact coefficient in response to the impact drop. The impact coefficient is a value used to show the offset situation of the rotor, and the quotient of the impact drop and the magnetic field intensity is used as the impact coefficient; Step 206: When the impact coefficient is higher than a preset coefficient threshold, determine the offset distance in response to the impact coefficient; Step 207: Based on the offset distance, control a preset control terminal to issue an offset alarm.

3. A method for anti-harmonic of a permanent magnet motor according to claim 2, characterized in that The rotor detection method further includes: Step 208: When the impact coefficient is higher than a preset coefficient threshold, determine the offset direction in response to the strong magnetic position, impact drop, and intensity drop, where the offset direction refers to the direction in which the rotor is offset; Step 209: Determine the correction intensity in response to the offset direction, offset distance, and magnetic field intensity; Step 210: Determine the test intensity in response to the correction intensity, influence coefficient, and test current; Step 211: Determine the test distribution in response to the test intensity; Step 212: Determine the strong magnetic volume in response to the test distribution; Step 213: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the demagnetized position in response to the test distribution; Step 214: Based on the demagnetized position, control a preset control terminal to issue a demagnetization alarm.

4. A method for anti-harmonic of a permanent magnet motor according to claim 3, characterized in that, The rotor detection method further includes: Step 215: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the magnetic supplement travel in response to the demagnetized position; Step 216: Control a preset magnetic supplement device to move to the demagnetized position according to the magnetic supplement travel, and determine the demagnetized volume in response to the demagnetized position; Step 217: Determine the magnetic supplement intensity in response to the demagnetized volume; Step 218: Control a preset magnetic supplement device to emit a magnetic field according to the magnetic supplement intensity, and control a preset test device to input a permanent magnet motor according to the test current to update the motor temperature; Step 219: When the motor temperature is not greater than a preset rotor threshold, based on the demagnetized position and demagnetized volume, control a preset control terminal to issue a magnetic supplement suggestion.

5. A method for suppressing harmonics of a permanent magnet motor according to claim 4, characterized in that, The method for determining the rotor threshold includes: Step 220: When the strong magnetic volume is lower than a preset strong magnetic threshold, determine the cooling rate in response to the motor temperature; Step 221: Determine the temperature difference in response to the motor temperature and usage threshold; Step 222: Determine the correction threshold in response to the motor temperature, temperature difference, and cooling rate; Step 223: Determine the rotor threshold in response to the magnetic supplement intensity and correction threshold.

6. A method for a permanent magnet motor to resist harmonics according to claim 5, characterized in that, It further includes a magnetic supplement method, and the magnetic supplement method includes: Step 300: When the motor temperature is not greater than a preset rotor threshold, determine the magnetic supplement quantity in response to the magnetic supplement intensity; Step 301: Determine the demagnetized area in response to the demagnetized position; Step 302: Determine the single-layer quantity in response to the demagnetized area; Step 303: Determine the magnetic addition travel in response to the magnetic supplement quantity, single-layer quantity, and demagnetized area; Step 304: Control a preset test device to adhere a preset magnetic block to the demagnetized area according to the magnetic addition travel.

7. A method for anti - harmonic of a permanent - magnet motor according to claim 6, characterized in that, The magnetic supplement method further includes: Step 305: When the magnetic supplement quantity is not less than the single-layer quantity, determine the barrier thickness in response to the magnetic supplement quantity; Step 306: Determine the permanent magnet boundary in response to the demagnetized area and test distribution; Step 307: Determine the injection travel in response to the barrier thickness and permanent magnet boundary; Step 308: Control a preset glue injection device to inject glue on the permanent magnet boundary according to the injection stroke.

8. A method for anti-harmonic of a permanent magnet motor according to claim 7, characterized in that, It further includes an inverter selection method, and the inverter selection method includes: Step 400: When the motor temperature is greater than a preset usage threshold, determine the harmonic amplitude in response to the motor temperature; Step 401: Determine the inverter voltage drop in response to the harmonic amplitude; Step 402: Determine the inverter number in response to the motor model and the inverter voltage drop; Step 403: Based on the inverter number, control a preset control terminal to display anti-harmonic suggestions.

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