CN116718915A - Motor notch electric field intensity detection method and device, electronic equipment and storage medium - Google Patents
Motor notch electric field intensity detection method and device, electronic equipment and storage medium Download PDFInfo
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- 230000005684 electric field Effects 0.000 title claims abstract description 204
- 238000001514 detection method Methods 0.000 title claims abstract description 62
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- 238000004364 calculation method Methods 0.000 description 10
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- 229910052802 copper Inorganic materials 0.000 description 5
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- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
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- 238000012360 testing method Methods 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02T10/64—Electric machine technologies in electromobility
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Abstract
The invention provides a motor notch electric field intensity detection method, a motor notch electric field intensity detection device, electronic equipment and a storage medium, wherein the motor notch electric field intensity detection device comprises: the device comprises a stator sample, a stator bar, a power supply, an electrometer, a processor and a plurality of induction loops; the stator sample includes at least one slot; the stator bar is arranged in a groove formed in the stator sample, the stator bar is sequentially wrapped with a groove insulating layer and an anti-corona layer, and two ends of the stator bar extend out of the notch of the stator sample; the induction rings are sleeved at one end of the stator bar, are positioned outside the grooves of the stator sample, and are positioned between the induction rings and the stator bar; the electrometer is used for respectively detecting the electric potentials of a plurality of induction rings when the two ends of the stator bar are connected with a power supply; the processor is used for determining the electric field intensity distribution at the notch of the stator sample according to the electric potentials of the plurality of induction rings. The scheme can improve the accuracy of the detection result of the electric field intensity at the notch of the stator.
Description
Technical Field
The present invention relates to the field of electrical engineering, and in particular, to a method and apparatus for detecting electric field strength of a motor slot, an electronic device, and a storage medium.
Background
In a high-voltage motor, most of leakage charges at the end part of a stator bar are concentrated on a capacitor close to a stator slot, so that an electric field at the stator slot is concentrated, corona discharge is easy to occur, and therefore, an anti-corona system is required to be arranged for the stator bar so as to uniformly distribute the electric field on the surface of the end part of the stator bar, and the end part of the stator bar is prevented from generating corona discharge due to overhigh local electric field intensity when voltage is applied. In the motor design process, the anti-corona effect of the stator bar anti-corona system needs to be detected so as to provide support for the selection of a motor insulation scheme and the safe operation.
At present, the anti-corona effect of the stator bar anti-corona system is detected by carrying out simulation calculation on the electric potential and the electric field intensity at the notch of the stator.
However, the electric potential and the electric field intensity at the notch of the stator are determined through a simulation calculation mode, and the simulation calculation mode has a large influence on a simulation calculation result, so that the accuracy of a detection result is poor.
Disclosure of Invention
In view of this, the method, the device, the electronic equipment and the storage medium for detecting the electric field intensity of the motor notch can improve the accuracy of the detection result of the electric field intensity at the stator notch.
According to a first aspect of an embodiment of the present invention, there is provided a motor slot electric field intensity detection device, including: the device comprises a stator sample, a stator bar, a power supply, an electrometer, a processing unit and a plurality of induction rings; the stator sample comprises at least one groove, the structure of a notch on the stator sample is the same as that of a stator notch in a motor to be detected, and the grounding point of the stator sample is grounded; the stator bar is arranged in a groove formed in the stator sample, a groove insulating layer and an anti-corona layer are sequentially wrapped on the stator bar, two ends of the stator bar extend out of a notch of the stator sample, the stator bar has the same structure as a stator winding in the motor to be detected, and the stator sample and the stator bar are subjected to paint dipping treatment; the induction rings are sleeved at one end of the stator bar, the induction rings are positioned outside the grooves of the stator sample, and the anti-corona layer is positioned between the induction rings and the stator bar; the electrometer is used for respectively detecting the electric potentials of the induction rings when the two ends of the stator bar are connected with the power supply; the processing unit is used for determining the electric field intensity distribution at the notch of the stator sample according to the electric potentials of the induction rings.
In a first possible implementation manner, with reference to the first aspect, sample pressing plates are disposed at two ends of the stator sample along an axial direction of the slot on the stator sample, and structures and materials of the sample pressing plates are matched with structures and materials of pressing plates at two ends of the stator in the motor to be detected.
In a second possible implementation manner, with reference to the first aspect, an inner ring of the induction ring is attached to a paint dipping layer outside the stator bar, and a center line of the induction ring is perpendicular to an axis of the stator bar.
In a third possible implementation, in combination with the second possible implementation, the electrometer is electrically connected to the induction loop by a lead, the lead being perpendicular to the axis of the stator bar.
In a fourth possible implementation manner, in combination with the third possible implementation manner, an insulation structure is disposed at a closed position of the induction loop and a connection position of the induction loop and the lead.
In a fifth possible implementation manner, with reference to the first aspect or any possible implementation manner of the first aspect, the electrometer is configured to detect first potentials of the plurality of induction loops when two ends of the stator bar are connected to a positive electrode of the power supply and a negative electrode of the power supply is connected to a ground point of the stator sample, and detect second potentials of the plurality of induction loops when two ends of the stator bar are connected to the negative electrode of the power supply and the positive electrode of the power supply is connected to the ground point of the stator sample; the processing unit is used for determining the electric field intensity distribution at the notch of the stator sample according to the first electric potential and the second electric potential of the plurality of induction rings.
In a sixth possible implementation manner, with reference to the fifth possible implementation manner, the processing unit is configured to perform the following processing: according to the capacitance value of the paint layer outside the stator bar and the capacitance value of the electrometer, carrying out error correction on the first potential to obtain a third potential, and carrying out error correction on the second potential to obtain a fourth potential; calculating the ratio of the difference of the third electric potential of two adjacent induction loops to the distance between the two induction loops to obtain the first electric field intensity between the two induction loops; calculating the ratio of the difference of the fourth electric potential of two adjacent induction loops to the distance between the two induction loops to obtain the second electric field intensity between the two induction loops; determining a first distribution curve according to each first electric field intensity, and determining a second distribution curve according to each second electric field intensity, wherein the first distribution curve and the second distribution curve are used for indicating the change of the electric field intensity of the surface of the stator bar along with the distance from the notch of the stator sample; and determining a third distribution curve for indicating the electric field intensity distribution at the notch of the stator sample according to the first distribution curve and the second distribution curve, wherein the third distribution curve is used for indicating the electric field intensity of the surface of the stator bar and changes along with the distance from the notch of the stator sample.
In a seventh possible implementation manner, with reference to the sixth possible implementation manner, the processing unit is configured to determine an intersection point of the first distribution curve and the second distribution curve, determine a curve segment corresponding to a distance between the intersection point and the notch of the stator sample in the first distribution curve as a first curve segment, determine a curve segment corresponding to a distance between the intersection point and the notch of the stator sample in the second distribution curve as a first curve segment, determine a curve segment corresponding to a distance between the notch of the stator sample in the second distribution curve and the notch of the stator sample as a second curve segment, and determine a curve matching the first curve segment and the second curve segment as the third distribution curve.
According to a second aspect of the embodiment of the present invention, there is provided a motor slot electric field intensity detection method, including: the method comprises the steps that potentials of a plurality of induction rings are obtained when two ends of a stator bar are connected with a power supply, wherein the stator bar is arranged in a groove formed in a stator sample, the structure of a notch on the stator sample is identical to that of a stator notch in a motor to be detected, the grounding point of the stator sample is grounded, a groove insulating layer and an anti-corona layer are sequentially wrapped on the stator bar, two ends of the stator bar extend out of the notch of the stator sample, the stator bar is identical to that of a stator winding in the motor to be detected, the stator sample and the stator bar are subjected to dip coating treatment, the induction rings are sleeved at one end of the stator bar, the induction rings are positioned outside the groove of the stator sample, and the anti-corona layer is positioned between the induction rings and the stator bar; and determining the electric field intensity distribution at the notch of the stator sample according to the electric potentials of the induction rings.
In a first possible implementation manner, with reference to the second aspect, the acquiring potentials of the plurality of induction loops when the two ends of the stator bar are connected to a power source includes: respectively obtaining first potentials and second potentials of the plurality of induction loops, wherein the first potentials are potentials of the induction loops when two ends of the stator bar are connected with a positive electrode of the power supply and a negative electrode of the power supply is connected with a grounding point of the stator sample, and the second potentials are potentials of the induction loops when two ends of the stator bar are connected with the negative electrode of the power supply and a positive electrode of the power supply is connected with the grounding point of the stator sample; the determining the electric field intensity distribution at the notch of the stator sample according to the electric potentials of the plurality of induction rings comprises the following steps: and determining the electric field intensity distribution at the notch of the stator sample according to the first electric potential and the second electric potential of the plurality of induction rings.
In a second possible implementation manner, with reference to the first possible implementation manner, the determining, according to the first electric potential and the second electric potential of the plurality of induction loops, an electric field intensity distribution at a notch of the stator sample includes: according to the capacitance value of the paint layer outside the stator bar and the capacitance value of the electrometer, carrying out error correction on the first potential to obtain a third potential, and carrying out error correction on the second potential to obtain a fourth potential; calculating the ratio of the difference of the third electric potential of two adjacent induction loops to the distance between the two induction loops to obtain the first electric field intensity between the two induction loops; calculating the ratio of the difference of the fourth electric potential of two adjacent induction loops to the distance between the two induction loops to obtain the second electric field intensity between the two induction loops; determining a first distribution curve according to each first electric field intensity, and determining a second distribution curve according to each second electric field intensity, wherein the first distribution curve and the second distribution curve are used for indicating the electric field intensity of the surface of the stator bar and change along with the distance from the notch of the stator sample; and determining a third distribution curve for indicating the electric field intensity distribution at the notch of the stator sample according to the first distribution curve and the second distribution curve, wherein the third distribution curve is used for indicating the electric field intensity of the surface of the stator bar and changes along with the distance from the notch of the stator sample.
In a third possible implementation manner, with reference to the second possible implementation manner, the determining, according to the first distribution curve and the second distribution curve, a third distribution curve for indicating an electric field intensity distribution at a notch of the stator sample includes: determining an intersection point of the first distribution curve and the second distribution curve; determining a curve segment corresponding to the first distribution curve, wherein the distance between the curve segment and the stator sample notch is larger than the distance between the intersection point and the stator sample notch, as a first curve segment; determining a curve segment, corresponding to the second distribution curve, with a distance from the stator sample notch smaller than a distance between the intersection point and the stator sample notch as a second curve segment; and determining a curve matched with the first curve segment and the second curve segment as the third distribution curve.
In a third aspect, an embodiment of the present invention further provides an electronic device, including: the device comprises a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface complete communication with each other through the communication bus; the memory is configured to store at least one executable instruction, where the executable instruction causes the processor to perform operations corresponding to a motor slot electric field intensity detection method provided in the second aspect or any possible implementation manner of the second aspect.
In a fourth aspect, embodiments of the present invention also provide a computer readable storage medium having stored thereon computer instructions that, when executed by a processor, cause the processor to perform a motor slot electric field intensity detection method as provided in the second aspect or any one of the possible implementations of the second aspect.
In a fifth aspect, embodiments of the present invention also provide a computer program comprising computer executable instructions which, when executed, cause at least one processor to perform the method for detecting electric field strength of a motor slot as provided in the second aspect or any one of the possible implementations of the second aspect.
In a sixth aspect, embodiments of the present invention also provide a computer program product tangibly stored on a computer-readable medium and comprising computer-executable instructions that, when executed, cause at least one processor to perform the motor slot electric field strength detection method as provided by the second aspect or any one of the possible implementations of the second aspect.
According to the technical scheme, the interface of the notch on the stator sample is identical to the structure of the notch of the stator in the motor to be detected, and the structure of the stator bar is identical to the structure of the stator winding in the motor to be detected, so that the stator in the motor to be detected can be simulated through the stator sample and the stator bar, and the electric field intensity of the notch of the stator of the motor can be detected. The stator bar is sleeved with a plurality of induction rings, when the stator bar is connected with a power supply, the induction rings can generate induction voltage, the potential of the induction rings can be detected through the electrometer, then the processing unit can determine the electric field intensity distribution at the notch of the stator sample according to the potential of each induction ring, and the determined electric field intensity distribution can be used as the electric field intensity distribution at the notch of the stator of the motor to be detected. Therefore, the electric field intensity distribution at the notch of the motor stator to be detected is determined in a direct measurement mode, the detection process is simple to operate, and interference factors causing errors of detection results are not easy to occur, so that the accuracy of the detection results can be improved.
Drawings
Fig. 1 is a schematic diagram of a motor slot electric field intensity detection device according to an embodiment of the present invention;
FIG. 2 is a schematic illustration of a positive connection provided by an embodiment of the present invention;
FIG. 3 is a schematic diagram of a reverse connection method according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a potential distribution curve according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an electric field intensity distribution curve according to an embodiment of the present invention;
FIG. 6 is a flowchart of a method for detecting electric field intensity of a motor slot according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of an equivalent circuit corresponding to a positive connection method according to an embodiment of the present invention;
FIG. 8 is a schematic diagram of an equivalent circuit corresponding to a reverse connection method according to an embodiment of the present invention;
fig. 9 is a schematic diagram of an electronic device according to an embodiment of the present invention.
List of reference numerals:
Detailed Description
As described above, in the development and testing of the motor, it is necessary to detect the anti-corona effect of the stator bar anti-corona system in the motor, and then select an appropriate insulation scheme for the motor according to the detection result, so as to prevent corona discharge at the end of the stator bar due to too high local electric field intensity when voltage is applied, and ensure safe operation of the motor. The anti-corona effect of the stator bar anti-corona system can be represented by the electric potential or electric field intensity at the notch of the motor stator, so that the electric potential distribution or electric field intensity distribution at the notch of the motor stator can be used as the detection result of the anti-corona effect. At present, the potential or electric field intensity at the notch of the stator is determined by a simulation calculation mode, so that the anti-corona effect of the stator bar anti-corona system is determined, however, the potential or electric field intensity at the notch of the stator obtained by different simulation calculation modes is different, a large number of parameters are required to be input by the simulation calculation mode, and when the parameters are input incorrectly, the simulation analysis result is greatly influenced, so that the potential or electric field intensity at the notch of the stator determined by the simulation calculation mode is poor in accuracy, and misjudgment on the anti-corona effect of the stator bar anti-corona system is caused.
In the embodiment of the invention, the electric field intensity distribution at the notch of the stator sample is detected through the stator sample and the stator bar, and the electric field intensity distribution at the notch of the stator sample can be used as the electric field intensity distribution at the notch of the motor stator because the structure of the notch on the stator sample is the same as that of the stator notch in the motor. A plurality of induction rings are sleeved on the stator bar, induced voltage is generated on the induction rings when the stator bar is electrified, and the electric field intensity distribution at the notch of the stator sample can be determined by measuring the electric potential on the induction rings, so that the electric field intensity distribution at the notch of the motor stator is obtained. The electric field intensity distribution at the notch of the motor stator is obtained in a direct measurement mode, the detection process is simple to operate, interference factors are few, and the accuracy of a detection result can be improved.
The following describes in detail the motor slot electric field intensity detection device, method and electronic equipment provided by the embodiment of the invention with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a motor slot electric field intensity detection device according to an embodiment of the present invention. As shown in fig. 1, the motor slot electric field intensity detection device 10 includes: a stator sample 11, a stator bar 12, a power supply 13, an electrometer 14, a processing unit 15, and a plurality of induction loops 16.
The stator sample 11 comprises at least one groove, the structure of a notch on the stator sample 11 is the same as that of a motor stator notch to be detected, and a grounding point arranged on the stator sample 11 is grounded. The stator bar 12 is arranged in a groove included in the stator sample 11, the stator bar 12 is sequentially wrapped with a groove insulating layer 17 and an anti-corona layer 18, two ends of the stator bar 12 extend out of a notch of the stator sample 11, and the stator bar 12 has the same structure as a stator winding in a motor to be detected. The stator sample 11 and the stator bar 12 are subjected to paint dipping treatment, and a paint dipping layer is formed on the stator bar 12. A plurality of induction rings 16 are sequentially sleeved at one end of the stator bar 12, each induction ring 16 is positioned outside the groove of the stator sample 11, and an anti-corona layer 18 is positioned between the induction ring 16 and the stator bar 12.
When the two ends of the stator bar 12 are connected with the power supply 13, the electrometer 14 can respectively detect the electric potential of each induction loop 16, and the processing unit 15 can determine the electric field intensity distribution at the notch of the stator sample 11 according to the electric potential of each induction loop 16 detected by the electrometer 14.
The stator sample 11 comprises one or more slots, and the cross-sectional shape and the cross-sectional size of the slots on the stator sample 11 are the same as those of the slots on the stator of the motor to be detected, so that the structure of the slot positions on the stator sample 11 is the same as that of the slots of the stator of the motor to be detected. The material of the stator sample 11 is the same as that of the stator in the motor to be detected, and the stator sample 11 may be taken from the stator of the motor to be detected, for example, a part of the stator including three slots may be taken from one end of the stator of the motor to be detected as the stator sample 11. Along the axial direction of the slots, the length of the stator sample 11 may be less than or equal to the length of the stator in the motor to be detected, i.e. the length of the slots on the stator sample 11 may be less than or equal to the length of the slots on the stator in the motor to be detected.
The stator sample 11 may include a plurality of slots, but only one of the slots needs to be placed with the stator bar 12 for testing. The structure of the stator bar 12 is the same as that of a stator winding in a motor to be detected, namely, the structure of the stator bar 12 is the same as that of a bar in a stator slot of the motor to be detected, and specifically, the number of wires included in the stator bar 12, the diameter of the wires, the thickness of insulating paint outside the wires, the winding mode among the wires, the materials of the wires and the like are consistent with those of the stator winding in the motor to be detected. The length of the stator bar 12 is greater than the length of the slots on the stator sample 11 so that both ends of the stator bar 12 can extend out of the slots on the stator sample 11. The stator bar 12 may be cut from a stator winding in the motor to be detected, and the winding in a stator slot in the motor to be detected and the parts extending out of both ends of the slot are cut to be used as the stator bar 12.
At both ends of the stator bar 12, a plurality of wires included in the stator bar 12 are electrically connected to a power source 13. The power supply 13 may be a direct current voltage source or a single-phase alternating current voltage source, and the power supply 13 may provide a voltage amplitude identical to a voltage fundamental amplitude of the input stator winding when the motor to be detected is rated to operate. If the power supply 13 is a single-phase alternating-current voltage source, the power supply 13 can provide voltage of the working frequency of the motor to be detected, and the harmonic voltage factor needs to meet the operation requirement of the motor to be detected.
The stator bar 12 is sequentially wrapped with a slot insulating layer 17 and an anti-corona layer 18, the slot insulating layer 17 is positioned between the stator bar 12 and the anti-corona layer 18, the material and wrapping mode of the slot insulating layer 17 are the same as those of slot insulation in a motor to be detected, and the material and wrapping mode of the anti-corona layer 18 are the same as those of the anti-corona layer on a stator winding in the motor to be detected. Anti-corona layer 18 may be formed by wrapping a low-resistance anti-corona tape in a half-fold, meaning that adjacent anti-corona tapes have half-corona-tape width overlap.
The anti-corona layer 18 is wrapped outside the slot insulating layer 17, and the anti-corona layer 18 exceeds the notch position on the stator sample 11 by a distance, so that the anti-corona layer 18 exists at the position where the induction ring 16 is sleeved on the stator bar 12, and the anti-corona effect of the anti-corona layer 18 is detected. The induction rings 16 are sequentially sleeved at one end of the stator bar 12 along the axial direction of the stator bar 12, each induction ring 16 is positioned outside a groove of the stator sample 11, distances between different induction rings 16 and notches on the stator sample 11 are different, and an anti-corona layer 18 exists between each induction ring 16 and the stator bar 12.
After the stator bar 12 is placed in the groove on the stator sample 11, the stator bar 12 and the stator sample 11 are subjected to a paint dipping process, and the process of the paint dipping process for the stator bar 12 and the stator sample 11 is the same as the paint dipping process when the motor stator to be detected is produced. After the stator bar 12 and the stator sample 11 are subjected to paint dipping treatment, a paint layer 19 is formed on the anti-corona layer 18 positioned outside the slots of the stator sample 11 and the slot insulating layer 17 not covered by the anti-corona layer 18, so that the induction ring 16 is sleeved outside the paint layer 19.
The induction loop 16 is made of a conductive material, for example, the induction loop 16 may be formed of copper wires end to end, ensuring that the induction loop 16 is able to generate an induced voltage when the stator bar 12 is connected to the power source 13. The plurality of induction rings 16 are distributed in sequence along the axial direction of the stator bar 12, and distances between the different induction rings 16 and the notch positions on the stator sample 11 are different, so that the distribution of the electric field intensity at the notch positions on the stator sample 11 can be determined according to the electric potential of each induction ring 16.
Since the induction loop 16 generates an induced voltage when the stator bar 12 is connected to the power source 13, the potential of the induction loop 16 needs to be measured when the stator bar 12 is connected to the power source 13. If the number of the electrometers 14 is plural, each sensing ring 16 may be connected to one electrometer 14, and different sensing rings 16 may be connected to different electrometers 14, and when the stator bar 12 is connected to the power source 13, the potential of the sensing ring 16 connected thereto may be measured by each electrometer 14. If the number of electrometers 14 is one, it is necessary to switch on the stator bar 12 to the power supply 13 a plurality of times, each time the potential of one induction loop 16 is measured by the electrometer 14.
The induction loops 16 generate induced electromotive forces in response to the electric field between the stator bar 12 and the stator sample 11, so that the electric potential of the induction loops 16 is related to the strength of the electric field between the stator bar 12 and the stator sample 11, and the difference in electric potential between the different induction loops 16 is related to the distribution of the electric field strength between the stator bar 12 and the stator sample 11, so that the processing unit 15 can determine the electric field strength distribution at the notch of the stator sample 11 from the electric potential of each induction loop 16.
In the embodiment of the invention, the interface of the notch on the stator sample 11 is the same as the structure of the stator notch in the motor to be detected, and the structure of the stator bar 12 is the same as the structure of the stator winding in the motor to be detected, so that the stator in the motor to be detected can be simulated through the stator sample 11 and the stator bar 12 to detect the electric field strength of the stator notch of the motor. The stator bar 12 is sleeved with a plurality of induction rings 16, when the stator bar 12 is connected with the power supply 13, the induction rings 16 generate induction voltage, the potential of the induction rings can be detected through the electrometer 14, then the processing unit 15 can determine the electric field intensity distribution at the notch of the stator sample 11 according to the potential of each induction ring 16, and the determined electric field intensity distribution can be used as the electric field intensity distribution at the notch of the stator of the motor to be detected. Therefore, the electric field intensity distribution at the notch of the motor stator to be detected is determined in a direct measurement mode, the detection process is simple to operate, and interference factors causing errors of detection results are not easy to occur, so that the accuracy of the detection results can be improved.
In one possible implementation, sample pressure plates are arranged at two ends of the stator sample 11 along the axial direction of the grooves on the stator sample 11, and the structures and materials of the sample pressure plates are matched with those of the pressure plates at two ends of the stator in the motor to be detected.
Pressing plates are respectively arranged at two ends of the motor stator, and the pressing plates at two ends of the stator are connected through iron bars so as to fix silicon steel sheets forming the stator core. In order to ensure the electric field intensity distribution at the notch of the stator sample 11, the same as the electric field intensity distribution at the notch of the motor to be detected, sample pressure plates are arranged at two ends of the stator sample 11 along the axial direction of the upper groove of the stator sample 11. The material of the sample pressing plate is the same as that of the pressing plates at two ends of the stator in the motor to be detected. The thickness of the sample pressing plate is the same as that of the pressing plates at two ends of the stator in the motor to be detected. The sample pressing plate can be cut from pressing plates at two ends of a stator in the motor to be detected, for example, the pressing plates at two ends of the stator in the motor to be detected are of circular annular sheet structures, then the fan annular sheet structures can be cut from the pressing plates at two ends of the stator in the motor to be detected to serve as sample pressing plates, and the cut fan annular sheet structures are matched with the shape of the stator sample 11.
In the embodiment of the invention, the two ends of the stator sample 11 are respectively provided with the sample pressing plates, and the structures and materials of the sample pressing plates are matched with those of the pressing plates at the two ends of the stator in the motor to be detected, so that the electric field intensity at the notch of the stator sample 11 is more similar to that at the notch of the motor to be detected, and the accuracy of detecting the electric field intensity at the notch of the motor can be improved.
In one possible implementation, the inner ring of the induction ring 16 is bonded to the paint impregnated layer 19 outside the stator bar 12, and the centerline of the induction ring 16 is perpendicular to the axis of the stator bar 12.
The center line of the induction ring 16 refers to the line connecting the center points of any radial cross section of the induction ring 16, and when the induction ring 16 is formed by connecting copper wires in an end-to-end manner, the center line of the induction ring 16 is the axis of the copper wires forming the induction ring 16. The centerline of the induction ring 16 is perpendicular to the axis of the stator bar 12, i.e., the axis of the induction ring 16 coincides with the axis of the stator bar 12.
The inner ring of the induction ring 16 is attached to the paint dipping layer 19 outside the stator bar 12 such that the induction ring 16 is snugly attached to the paint dipping layer 19. When the induction ring 16 is sleeved at one end of the stator bar 12, the copper wires can be bound to the stator bar 12 and then connected end to form the induction ring 16, so that the induction ring 16 is closely attached to the paint dipping layer 19.
In the embodiment of the invention, the induction ring 16 is attached to the paint dipping layer 19 outside the stator bar 12, so that the large error of the detected potential caused by the serial connection of the induction ring 16 into an air gap can be prevented, and the accuracy of the detected induction field intensity at the notch of the stator sample 11 is ensured. The center line of the induction ring 16 is perpendicular to the axis of the stator bar 12, so that the electric field intensity of the position of the induction ring 16 can be accurately reflected, and the accuracy of the detected electric field intensity at the notch of the stator sample 11 is further ensured.
In one possible implementation, the electrometer 14 is electrically connected to the induction loop 16 by leads that are perpendicular to the axis of the stator bar 12.
The electrometer 14 needs to be electrically connected to each sensing ring 16 to detect the electric potential of each sensing ring 16, so that the electrometer 14 is electrically connected to the sensing rings 16, and leads electrically connected to the sensing rings 16 are provided, and different sensing rings 16 are connected to different leads, so that when the electric potential of the sensing rings 16 is detected by the electrometer 14, the electrometer 14 is electrically connected to the sensing rings 16 through the leads connected to the sensing rings 16, and then the electric potential of the sensing rings 16 is detected through the leads.
In the embodiment of the invention, the electrometer 14 is electrically connected with the induction ring 16 through the lead, the lead is perpendicular to the axis of the stator bar 12, and the interference of the induction electric field generated by the stator bar 12 caused by the induction electric field generated when the lead is electrified is avoided, so that the electric field intensity at the notch of the stator sample 11 can be accurately reflected by the electric field detected by the electrometer 14, and the accuracy of the detected electric field intensity distribution at the notch of the stator sample 11 is further ensured.
In one possible implementation, the closed position of the inductive loop 16, and the connection of the inductive loop 16 to the lead, are provided with insulating structures.
In the embodiment of the invention, the induction ring 16 is formed by connecting copper wires end to end, an insulating structure is arranged at the closed position of the induction ring 16, and an insulating structure is arranged at the connection position of the induction ring 16 and a lead wire, so that the occurrence of point discharge is prevented, the safety of the detection process is ensured, and the accuracy of detecting the potential of the induction ring 16 is ensured. Insulating coatings, such as insulating paint, may be applied to the closed position of the inductor loop 16 and to the connection of the inductor loop 16 to the lead to form an insulating structure.
In one possible implementation, when the potential of the induction loop 16 is detected by the electrometer 14, a first potential of the induction loop 16 when both ends of the stator bar 12 are connected to the positive electrode of the power supply 13 and a second potential of the induction loop 16 when both ends of the stator bar 12 are connected to the negative electrode of the power supply 13 may be detected, respectively, and the processing unit 15 determines the electric field intensity distribution at the notch of the stator sample 11 according to the first potential and the second potential of each induction loop 16.
The connection between the two ends of the stator bar 12 and the positive electrode of the power supply 13 and the connection between the ground point on the stator sample 11 and the negative electrode of the power supply 13 are defined as positive connections, as shown in fig. 2. The connection between the two ends of the stator bar 12 and the negative electrode of the power supply 13 and the connection between the ground point on the stator sample 11 and the positive electrode of the power supply 13 are defined as reverse connections, as shown in fig. 3.
As shown in fig. 2, when the potential of the induction loop 16 is detected by the positive connection method, for example, the high voltage end of the electrometer 14 is electrically connected to the induction loop 16 through a lead wire, the low voltage end of the electrometer 14 is grounded, and when the two ends of the stator bar 12 are connected to the positive electrode of the power supply 13, the potential of the induction loop 16 is detected by the electrometer 14, and the detection result is used as the first potential of the induction loop 16. The first potential of each sensing loop 16 is detected by connecting the electrometer 14 to a different sensing loop 16.
As shown in fig. 3, when the potential of the induction loop 16 is detected by the reverse connection method, the high voltage end of the electrometer 14 is grounded, the low voltage end of the electrometer 14 is electrically connected to the induction loop 16, for example, the low voltage end of the electrometer 14 is electrically connected to the induction loop 16 through a lead wire, when both ends of the stator bar 12 are connected to the negative electrode of the power supply 13, the potential of the induction loop 16 is detected by the electrometer 14, and the detection result is used as the second potential of the induction loop 16. The second potential of each sensing loop 16 is detected by connecting the electrometer 14 to a different sensing loop 16.
Fig. 4 is a potential profile of an embodiment of the present invention. As shown in fig. 4, the abscissa indicates the distance between the point on the paint dipping layer 19 and the notch on the stator sample 11 in the axial direction of the stator bar 12, and the ordinate indicates the potential. Curve 401 is a plot of the surface potential of the paint impregnated layer 19 as a function of distance from the notch of the stator sample 11 as detected by the reverse connection. Curve 402 is a plot of the surface potential of the paint impregnated layer 19 as a function of distance from the notch of the stator sample 11 as detected by the positive connection.
In the embodiment of the invention, when the electric potential of the induction ring 16 is detected in a positive connection mode, the detection result of the electric potential near the notch of the stator sample 11 is more accurate, the error of the detection result of the electric potential far from the notch of the stator sample 11 is larger, and when the electric potential of the induction ring 16 is detected in a reverse connection mode, the error of the detection result of the electric potential near the notch of the stator sample 11 is larger, the detection result of the electric potential far from the notch of the stator sample 11 is more accurate, namely the first electric potential near the notch of the stator sample 11 is more average, the second electric potential far from the induction ring 16 at the notch of the stator sample 11 is more accurate, therefore, the first electric potential and the second electric potential of the induction ring 16 can be detected respectively, and the electric field intensity distribution at the notch of the stator sample 11 can be determined according to the first electric potential and the second electric potential of each induction ring 16.
The reason why the difference in accuracy of the detection result is caused by the forward connection method and the reverse connection method will be described in detail in the following examples.
In one possible implementation, the processing unit 15 may perform the following steps to determine the electric field intensity distribution at the notch of the stator sample 11 from the first and second electric potentials of the induction loop 16:
S1: and according to the capacitance value of the paint layer 19 outside the stator bar 12 and the capacitance value of the electrometer 14, performing error correction on the first potential to obtain a third potential, and performing error correction on the second potential to obtain a fourth potential.
Since the capacitance of the paint layer 19 outside the anti-corona layer 18 and the capacitance of the electrometer 14 have a voltage dividing effect, when an induced voltage is generated on the induction ring 16, the detected potential is lower due to the voltage dividing effect of the capacitance of the paint layer 19 and the capacitance of the electrometer 14, so that the potential measurement result can be adjusted according to the capacitance of the paint layer 19 and the capacitance of the electrometer 14, that is, the potential measurement result is multiplied by a coefficient greater than 1, so as to balance the influence of the capacitance of the paint layer 19 and the capacitance of the electrometer 14 on the potential measurement result. After the correction coefficient is determined according to the capacitance value of the paint layer 19 and the capacitance value of the electrometer 14, the product of each first potential and the correction coefficient is calculated as a third potential corresponding to the first potential, and the product of each second potential and the correction coefficient is calculated as a fourth potential corresponding to the second potential, wherein the correction coefficient is greater than 1.
The conventional technical means in the art when the potential detection result is corrected according to the voltage division effect of the capacitor are not described herein.
S2: the ratio of the difference between the third potentials of the adjacent two induction loops 16 to the distance between the two induction loops 16 is calculated to obtain the first electric field strength between the two induction loops 16.
The plurality of induction rings 16 are arranged in sequence along the axial direction of the stator bar 12, and the distances between adjacent induction rings 16 are equal. The third potential of two adjacent inductive loops 16 is subtracted by the distance between the adjacent inductive loops 16 to obtain the electric field strength between the two inductive loops 16, which is determined as the first electric field strength between the two inductive loops 16.
If the power source 13 is an ac voltage source, the potentials will have a phase difference under ac excitation, but the phase difference is negligible, so that the third potential of two adjacent induction loops 16 can be subtracted and divided by the distance between the adjacent induction loops 16 to obtain the first electric field strength between the two induction loops 16.
It should be noted that, the distance between the adjacent induction loops 16 is just one implementation, and does not limit the distance between the induction loops 16, in other examples, the distance between two induction loops 16 included in different adjacent induction loop pairs may be different, where when calculating the first electric field strength between two adjacent induction loops 16, the third electric potential of the two induction loops 16 is subtracted by the distance between the two induction loops 16, and the calculated result is taken as the first electric field strength between the two induction loops 16.
S3: the ratio of the difference in the fourth potential of the adjacent two induction loops 16 to the distance between the two induction loops 16 is calculated to obtain the second electric field strength between the two induction loops 16.
If the distances between adjacent inductive loops 16 are equal, the fourth potential of adjacent inductive loops 16 may be subtracted by the distance between adjacent inductive loops 16 to obtain the electric field strength between the two inductive loops 16, which is determined as the second electric field strength between the two inductive loops 16.
If the power source 13 is an ac voltage source, the potentials will have a phase difference under ac excitation, but the phase difference is negligible, so that the fourth potential of two adjacent induction loops 16 can be subtracted and divided by the distance between the adjacent induction loops 16 to obtain the second electric field strength between the two induction loops 16.
If the distances between the adjacent induction loops 16 are not equal, then the fourth potential of the two induction loops 16 is subtracted by the distance between the two induction loops 16 when calculating the second electric field strength between the two adjacent induction loops 16, and the result of the calculation is taken as the second electric field strength between the two induction loops 16.
S4: the first distribution curve is determined according to the first electric field intensities, and the second distribution curve is determined according to the second electric field intensities.
After calculating the first electric field intensity between each adjacent induction loop 16, fitting a first distribution curve according to the arrangement sequence of the induction loops 16, wherein the first distribution curve can indicate the change of the electric field intensity on the surface of the stator bar 12 along with the distance from the notch of the stator sample 11. After calculating the second electric field intensity between each adjacent induction loop 16, a second distribution curve is fitted according to the arrangement order of the induction loops 16, and the second distribution curve can indicate the change of the electric field intensity on the surface of the stator bar 12 along with the distance from the notch of the stator sample 11.
Fig. 5 is an electric field strength distribution curve of an embodiment of the present invention. As shown in fig. 5, the abscissa indicates the distance between the point on the paint layer 19 and the notch on the stator bar 11 in the axial direction of the stator bar 12, and the ordinate indicates the electric field strength. Curve 501 is a first distribution curve and curve 502 is a second distribution curve.
S5: from the first distribution curve and the second distribution curve, a third distribution curve for indicating the electric field intensity distribution at the notch of the stator sample 11 is determined.
The first distribution curve indicates the electric field intensity distribution at the notch of the stator sample 11 detected based on the positive connection mode, the second distribution curve indicates the electric field intensity distribution at the notch of the stator sample 11 detected based on the negative connection mode, the first distribution curve can more accurately indicate the electric field intensity distribution near the notch of the stator sample 11, the second distribution curve can more accurately indicate the electric field intensity distribution far away from the notch of the stator sample 11, so the first distribution curve and the second distribution curve can be combined to determine the third distribution curve, and the third distribution curve can more accurately indicate the electric field intensity distribution at the notch of the stator sample 11 on the whole. The third profile may indicate the electric field intensity distribution at the notch of the stator sample 11, and in particular may indicate the change in electric field intensity at the surface of the stator bar 12 as a function of the distance from the notch of the stator sample 11.
As shown in fig. 5, a third profile shown in curve 503 is determined from the first profile shown in curve 501 and the second profile shown in curve 502. For example, the envelope of the first distribution curve and the second distribution curve may be used as the third distribution curve.
In the embodiment of the invention, the electric potential measured by the positive connection mode and the negative connection mode is lower than the actual value, in order to solve the problem that the electric potential measured value is lower than the actual value, the electric field intensity distribution curve is used for replacing the electric potential distribution curve, the electric field intensity is calculated by dividing the electric potential of the adjacent induction rings 16 by the distance between the two induction rings 16, and the systematic error can be counteracted, so that the obtained third distribution curve can more accurately reflect the distribution of the electric field intensity at the notch of the stator in the motor to be detected, and further, whether the stator bar anti-corona system in the motor to be detected is reasonable in design or not can be accurately judged.
In one possible implementation, when the processing unit 15 determines the third distribution curve according to the first distribution curve and the second distribution curve, the processing unit 15 may determine an intersection point of the first distribution curve and the second distribution curve, then determine a curve segment corresponding to the first distribution curve, in which a distance between the intersection point and the notch of the stator sample 11 is smaller than a distance between the intersection point and the notch of the stator sample 11, as the first curve segment, determine a curve segment corresponding to the second distribution curve, in which a distance between the intersection point and the notch of the stator sample 11 is greater than a distance between the intersection point and the notch of the stator sample 11, as the second curve segment, and then determine a curve matching the first curve segment and the second curve segment as the third curve.
As shown in fig. 5, a curve 501 is a first distribution curve, a curve 502 is a second distribution curve, a curve segment on the curve 501, the corresponding abscissa of which is smaller than the abscissa of the intersection of the curve 501 and the curve 502, is determined as a first curve segment, a curve segment on the curve 502, the corresponding abscissa of which is larger than the abscissa of the intersection of the curve 501 and the curve 502, is determined as a second curve segment, and then a curve close to the trends of the first curve segment and the second curve segment is fitted as a third curve.
In the embodiment of the invention, the first distribution curve can more accurately indicate the electric field intensity distribution near the notch of the stator sample 11, and the second distribution curve can more accurately indicate the electric field intensity distribution far from the notch of the stator sample 11, so that the parts of the first distribution curve and the second distribution curve, which can accurately indicate the electric field intensity distribution near the notch of the stator sample 11, can be combined to determine the third distribution curve, and the third distribution curve can accurately indicate the electric field intensity distribution near and far from the notch of the stator sample 11.
The motor slot electric field intensity detection method according to the embodiment of the present invention will be described below with reference to the motor slot electric field intensity detection device provided in the above embodiment, and unless otherwise specified, the stator sample, the stator bar, the power supply, the electrometer, the processing unit, the induction ring, the slot insulation layer, the anti-corona layer, and the paint dipping layer in the motor slot electric field intensity detection method embodiment may be the stator sample 11, the stator bar 12, the power supply 13, the electrometer 14, the processing unit 15, the induction ring 16, the slot insulation layer 17, the anti-corona layer 18, and the paint dipping layer 19 in this order.
Fig. 6 shows a flowchart of a motor slot electric field intensity detection method according to an embodiment of the present invention. As shown in fig. 6, the motor slot electric field intensity detection method 600 includes the following steps:
and 601, acquiring the electric potentials of a plurality of induction loops when the two ends of the stator bar are connected with a power supply.
When the two ends of the stator bar are connected with the power supply, an electric field is generated between the stator bar 12 and the stator sample 11, and then an induction voltage is generated by the induction rings positioned in the electric field, so that the electric potential of each induction ring can be detected when the two ends of the stator bar are connected with the power supply. The sensing ring is connected to an electrometer so that the potential of the sensing ring can be measured by the electrometer. When measuring the potential of different induction rings, the electrometer is connected with different induction rings, so that the potential of one induction ring can be measured by connecting the two ends of the stator bar with a power supply each time, and the potential of each induction ring is measured by connecting the two ends of the stator bar with the power supply for a plurality of times.
Step 602, determining the electric field intensity distribution at the notch of the stator sample according to the electric potential of each induction ring.
Since the induction loop generates induced electromotive force in response to an electric field between the stator bar and the stator sample, the electric potential of the induction loop is related to the strength of the electric field between the stator bar and the stator sample, and the difference in electric potential between different induction loops is related to the distribution of the electric field strength between the stator bar and the stator sample, the electric field strength distribution at the notch of the stator sample can be determined from the electric potentials of the respective induction loops.
In the embodiment of the invention, the interface of the notch on the stator sample is identical to the structure of the stator notch in the motor to be detected, and the structure of the stator bar is identical to the structure of the stator winding in the motor to be detected, so that the stator in the motor to be detected can be simulated through the stator sample and the stator bar to detect the electric field intensity of the stator notch of the motor. The stator bar is sleeved with a plurality of induction rings, when the stator bar is connected with a power supply, the induction rings can generate induction voltage, the electric field intensity distribution at the notch of a stator sample can be determined according to the electric potential of each induction ring by detecting the electric potential of the induction rings, and the determined electric field intensity distribution can be used as the electric field intensity distribution at the notch of the stator of the motor to be detected. Therefore, the electric field intensity distribution at the notch of the motor stator to be detected is determined in a direct measurement mode, the detection process is simple to operate, and interference factors causing errors of detection results are not easy to occur, so that the accuracy of the detection results can be improved.
In one possible implementation manner, when the electric potential of the induction ring is acquired, the first electric potential and the second electric potential of each induction ring can be acquired respectively, and then the electric field intensity distribution at the notch of the stator sample can be determined according to the first electric potential and the second electric potential of each induction ring. The first potential is the potential of the induction ring when the two ends of the stator bar are connected with the positive electrode of the power supply and the negative electrode of the power supply is connected with the grounding point of the stator sample, and the second potential is the potential of the induction ring when the two ends of the stator bar are connected with the negative electrode of the power supply and the positive electrode of the power supply is connected with the grounding point of the stator sample.
The first potential is the potential of the induction loop measured by adopting a positive connection mode, the second potential is the potential of the induction loop measured by adopting a negative connection mode, the positive connection mode is shown in fig. 2, and the negative connection mode is shown in fig. 3.
When the potential of the induction ring is measured in a positive connection mode, when the electrometer is connected to the induction ring and the two ends of the stator bar are connected with a power supply, the electric field intensity detection device of the motor notch can be simplified into an equivalent circuit shown in fig. 7 according to the current of the current. As shown in FIG. 7, Z A For representing the ratio of voltage to current at point A, i.e. the equivalent impedance at point A, Z 0 For indicating the capacitance between the electrometer's own electrodes, Z f For representing the equivalent capacitance of the additional insulation.
As shown in FIG. 7, R is the resistance of the stator sample notch to point A prior to electrometer accessThe voltage change at the point A after the electrometer is connected isCausing relative errors. According to the rough calculation, R and the surface resistance and the distance x between the measuring point and the notch of the stator sample are related,where l is the cross-sectional perimeter of the stator bar.
If the actual resistance of the anti-blooming layer is low, i.e,. When (when)In the time-course of which the first and second contact surfaces,the smaller x isThe smaller x is, the larger x isThe larger the error is at the end of the antihalation layer.
If the actual resistance of the anti-blooming layer is high, i.e。In the time-course of which the first and second contact surfaces,error ofClose to zero. When the measuring point is far away from the notch of the stator sample, R increases as x increases, even when R approachesIn this case, a large error is introduced when the electrometer is connected.
The above-mentioned error is for the change of the potential of the point A, in fact, if measured by electrometerRepresentative ofThere will be a fixed error due toAboutOne tenth of a, thereforeTo be used forRepresentative ofThere will be a fixing error of about 10%.
According to the above analysis, the potential measured by the positive connection method has a smaller error in the measurement result in the vicinity of the notch of the stator sample, the measured value is lower than the actual value by about 10%, and the greater the distance between the measurement point and the notch of the stator sample is, the greater the absolute error is, and the measured value is lower than the actual value.
When the potential of the induction ring is measured in a reverse connection mode, when the electrometer is connected to the induction ring and the two ends of the stator bar are connected with a power supply, the electric field intensity detection device of the motor notch can be simplified into an equivalent circuit shown in fig. 8 according to the current of the current. As shown in FIG. 8, the error in the potential at the point A when the electrometer is connected and when the electrometer is not connected is. According to、And R is a value satisfyingError of Close to zero. If measured by electrometerRepresentative ofThere will be about 10% fixing error because the closer to the stator sample notch the greater its absolute error.
In the embodiment of the invention, when the electric potential of the induction ring is measured by adopting the positive connection mode, the measurement result close to the notch of the stator sample is more accurate, and the measurement result far away from the notch of the stator sample is lower, so that the electric field intensity far away from the notch of the stator sample is lower.
When the electric potential of the induction ring is measured by adopting a positive connection mode and a reverse connection mode, the measured value is lower than the actual value, and in order to overcome the problem, the electric field intensity distribution curve can be used for replacing the electric potential distribution curve, and when two adjacent points are adjacent
In one possible implementation, when determining the electric field intensity distribution from the first potential and the second potential, the electric field intensity distribution may be determined by:
A1: and carrying out error correction on the first potential according to the capacitance value of the paint layer outside the stator bar and the capacitance value of the electrometer to obtain a third potential, and carrying out error correction on the second potential to obtain a fourth potential.
A2: and calculating the ratio of the difference of the third electric potential of the two adjacent induction loops to the distance between the two induction loops to obtain the first electric field intensity between the two induction loops.
A3: and calculating the ratio of the difference of the fourth electric potential of the two adjacent induction loops to the distance between the two induction loops to obtain the second electric field intensity between the two induction loops.
A4: the first distribution curve is determined according to the first electric field intensities, and the second distribution curve is determined according to the second electric field intensities.
The first distribution curve and the second distribution curve are used for indicating the electric field intensity of the surface of the stator bar and change along with the distance from the notch of the stator sample.
A5: a third distribution curve for indicating the electric field intensity distribution at the notch of the stator sample is determined from the first distribution curve and the second distribution curve.
The third profile is used to indicate the electric field strength at the surface of the stator bar as a function of distance from the notch of the stator sample.
In the embodiment of the invention, the electric potential measured by the positive connection mode and the negative connection mode is lower than the actual value, in order to solve the problem that the electric potential measured value is lower than the actual value, the electric field intensity distribution curve is used for replacing the electric potential distribution curve, the electric field intensity is calculated by dividing the electric potential of the adjacent induction rings by the distance between the two induction rings, and the systematic error can be counteracted, so that the obtained third distribution curve can more accurately reflect the distribution of the electric field intensity at the notch of the stator in the motor to be detected, and further, whether the stator bar anti-corona system in the motor to be detected is reasonable in design or not can be accurately judged.
In one possible implementation, when determining the third distribution curve according to the first distribution curve and the second distribution curve, an intersection point of the first distribution curve and the second distribution curve may be determined, then a curve segment corresponding to the first distribution curve, which is smaller than a distance between the intersection point and the stator sample notch, is determined as a first curve segment, a curve segment corresponding to the second distribution curve, which is greater than the distance between the intersection point and the stator sample notch, is determined as a second curve segment, and then a curve matched with the first curve segment and the second curve segment is determined as a third curve.
In the embodiment of the invention, the first distribution curve can accurately indicate the electric field intensity distribution close to the notch of the stator sample, and the second distribution curve can accurately indicate the electric field intensity distribution far away from the notch of the stator sample, so that the third distribution curve can be determined by integrating the parts of the first distribution curve and the second distribution curve, which can accurately indicate the electric field intensity distribution at the notch of the stator sample, and the third distribution curve can accurately indicate the electric field intensity distribution close to and far away from the notch of the stator sample.
It should be noted that, the motor slot electric field intensity detection method in each embodiment is implemented based on the motor slot electric field intensity detection device, and the motor slot electric field intensity detection method and the motor slot electric field intensity detection device are based on the same inventive concept, and each step included in the motor slot electric field intensity detection method may refer to the description in the foregoing motor slot electric field intensity detection device embodiment, which is not repeated herein.
Fig. 9 is a schematic diagram of an electronic device according to an embodiment of the present invention, which is not limited to the specific implementation of the electronic device according to the embodiment of the present invention. Referring to fig. 9, an electronic device 900 provided in an embodiment of the present invention includes: a processor 902, a communication interface (Communications Interface), a memory 906, and a communication bus 908. Wherein:
processor 902, communication interface 904, and memory 906 communicate with each other via a communication bus 908.
A communication interface 904 for communicating with other electronic devices or servers.
The processor 902 is configured to execute the program 910, and specifically may execute relevant steps in the foregoing embodiment of the method for detecting electric field strength of a motor slot.
In particular, the program 910 may include program code including computer-operating instructions.
The processor 902 may be a central processing unit, CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention. The one or more processors comprised by the smart device may be the same type of processor, such as one or more CPUs; but may also be different types of processors such as one or more CPUs and one or more ASICs.
A memory 906 for storing a program 910. Memory 906 may comprise high-speed RAM memory or may also include non-volatile memory (non-volatile memory), such as at least one disk memory.
The program 910 may be specifically configured to cause the processor 902 to perform the motor slot electric field intensity detection method in any of the foregoing embodiments.
The specific implementation of each step in the procedure 910 may refer to corresponding steps and corresponding descriptions in the units in the foregoing embodiment of the method for detecting electric field intensity of a motor slot, which are not repeated herein. It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the apparatus and modules described above may refer to corresponding procedure descriptions in the foregoing method embodiments, which are not repeated herein.
Through the electronic equipment of this embodiment, the interface of notch on the stator sample is the same with the structure of the stator notch in the motor that waits to detect, and the structure of stator bar is the same with the structure of the stator winding in the motor that waits to detect, so can simulate the stator in the motor that waits to detect through stator sample and stator bar to detect motor stator notch electric field intensity. The stator bar is sleeved with a plurality of induction rings, when the stator bar is connected with a power supply, the induction rings can generate induction voltage, the electric field intensity distribution at the notch of a stator sample can be determined according to the electric potential of each induction ring by detecting the electric potential of the induction rings, and the determined electric field intensity distribution can be used as the electric field intensity distribution at the notch of the stator of the motor to be detected. Therefore, the electric field intensity distribution at the notch of the motor stator to be detected is determined in a direct measurement mode, the detection process is simple to operate, and interference factors causing errors of detection results are not easy to occur, so that the accuracy of the detection results can be improved.
The present invention also provides a computer readable storage medium storing instructions for causing a machine to perform a motor slot electric field strength detection method as described herein. Specifically, a system or apparatus provided with a storage medium on which a software program code realizing the functions of any of the above embodiments is stored, and a computer (or CPU or MPU) of the system or apparatus may be caused to read out and execute the program code stored in the storage medium.
In this case, the program code itself read from the storage medium may realize the functions of any of the above-described embodiments, and thus the program code and the storage medium storing the program code form part of the present invention.
Examples of the storage medium for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (e.g., CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the program code may be downloaded from a server computer by a communication network.
Further, it should be apparent that the functions of any of the above-described embodiments may be implemented not only by executing the program code read out by the computer, but also by causing an operating system or the like operating on the computer to perform part or all of the actual operations based on the instructions of the program code.
Further, it is understood that the program code read out by the storage medium is written into a memory provided in an expansion board inserted into a computer or into a memory provided in an expansion module connected to the computer, and then a CPU or the like mounted on the expansion board or the expansion module is caused to perform part and all of actual operations based on instructions of the program code, thereby realizing the functions of any of the above embodiments.
The embodiment of the invention also provides a computer program, which comprises computer executable instructions, wherein the computer executable instructions, when executed, cause at least one processor to execute the motor slot electric field intensity detection method provided by the above embodiments.
Embodiments of the present invention also provide a computer program product tangibly stored on a computer-readable medium and including computer-executable instructions that, when executed, cause at least one processor to perform the motor slot electric field intensity detection method provided by the above embodiments. It should be understood that each solution in this embodiment has the corresponding technical effects in the foregoing method embodiments, which are not repeated herein.
It should be noted that not all the steps and modules in the above flowcharts and the system configuration diagrams are necessary, and some steps or modules may be omitted according to actual needs. The execution sequence of the steps is not fixed and can be adjusted as required. The system structure described in the above embodiments may be a physical structure or a logical structure, that is, some modules may be implemented by the same physical entity, or some modules may be implemented by multiple physical entities, or may be implemented jointly by some components in multiple independent devices.
Nouns and pronouns for humans in this patent application are not limited to a particular gender.
In the above embodiments, the hardware module may be mechanically or electrically implemented. For example, a hardware module may include permanently dedicated circuitry or logic (e.g., a dedicated processor, FPGA, or ASIC) to perform the corresponding operations. The hardware modules may also include programmable logic or circuitry (e.g., a general-purpose processor or other programmable processor) that may be temporarily configured by software to perform the corresponding operations. The particular implementation (mechanical, or dedicated permanent, or temporarily set) may be determined based on cost and time considerations.
While the invention has been illustrated and described in detail in the drawings and in the preferred embodiments, the invention is not limited to the disclosed embodiments, and it will be appreciated by those skilled in the art that the code audits of the various embodiments described above may be combined to produce further embodiments of the invention, which are also within the scope of the invention.
Claims (16)
1. A motor slot electric field strength detection device (10), comprising: a stator sample (11), a stator bar (12), a power supply (13), an electrometer (14), a processing unit (15) and a plurality of induction loops (16);
The stator sample (11) comprises at least one groove, the structure of a notch on the stator sample (11) is the same as that of a stator notch in a motor to be detected, and the grounding point of the stator sample (11) is grounded;
the stator bar (12) is arranged in a groove formed in the stator sample (11), a groove insulating layer (17) and an anti-corona layer (18) are sequentially wrapped on the stator bar (12), two ends of the stator bar (12) extend out of a notch of the stator sample (11), the stator bar (12) has the same structure as a stator winding in the motor to be detected, and the stator sample (11) and the stator bar (12) are subjected to paint dipping treatment;
the induction rings (16) are sleeved at one end of the stator bar (12), the induction rings (16) are positioned outside the grooves of the stator sample (11), and the anti-corona layer (18) is positioned between the induction rings (16) and the stator bar (12);
the electrometer (14) is used for respectively detecting the electric potentials of the plurality of induction rings (16) when the two ends of the stator bar (12) are connected with the power supply (13);
the processing unit (15) is used for determining the electric field intensity distribution at the notch of the stator sample (11) according to the electric potentials of the plurality of induction rings (16).
2. The device according to claim 1, characterized in that sample pressure plates are arranged at both ends of the stator sample (11) along the axial direction of the slots on the stator sample (11), the structure and material of the sample pressure plates being matched with the structure and material of the pressure plates at both ends of the stator in the motor to be tested.
3. The device according to claim 1, characterized in that the inner ring of the induction ring (16) is attached to a lacquer layer (19) outside the stator bar (12) and that the centre line of the induction ring (16) is perpendicular to the axis of the stator bar (12).
4. A device according to claim 3, characterized in that the electrometer (14) is electrically connected to the induction loop (16) by means of a lead, which is perpendicular to the axis of the stator bar (12).
5. The device according to claim 4, characterized in that the closed position of the induction loop (16) and the connection position of the induction loop (16) to the lead are provided with insulating structures.
6. The apparatus according to any one of claims 1 to 5, wherein,
the electrometer (14) is configured to detect first potentials of the plurality of induction rings (16) when both ends of the stator bar (12) are connected to the positive electrode of the power supply (13) and the negative electrode of the power supply (13) is connected to the ground point of the stator sample (11), and detect second potentials of the plurality of induction rings (16) when both ends of the stator bar (12) are connected to the negative electrode of the power supply (13) and the positive electrode of the power supply (13) is connected to the ground point of the stator sample (11);
The processing unit (15) is used for determining the electric field intensity distribution at the notch of the stator sample (11) according to the first electric potential and the second electric potential of the plurality of induction rings (16).
7. The apparatus according to claim 6, characterized in that the processing unit (15) is adapted to perform the following processing:
according to the capacitance value of the paint dipping layer (19) outside the stator bar (12) and the capacitance value of the electrometer (14), carrying out error correction on the first potential to obtain a third potential, and carrying out error correction on the second potential to obtain a fourth potential;
calculating the ratio of the difference between the third potentials of two adjacent induction loops (16) to the distance between the two induction loops (16) to obtain the first electric field intensity between the two induction loops (16);
calculating the ratio of the difference between the fourth potential of two adjacent induction loops (16) to the distance between the two induction loops (16) to obtain the second electric field intensity between the two induction loops (16);
determining a first distribution curve (501) according to each first electric field intensity, and determining a second distribution curve (502) according to each second electric field intensity, wherein the first distribution curve (501) and the second distribution curve (502) are used for indicating the change of the electric field intensity of the surface of the stator bar (12) along with the distance from a notch of the stator sample (11);
A third distribution curve (503) for indicating an electric field intensity distribution at a notch of the stator sample (11) is determined from the first distribution curve (501) and the second distribution curve (502), wherein the third distribution curve (503) is used for indicating the electric field intensity of the surface of the stator bar (12) as a function of the distance to the notch of the stator sample (11).
8. The apparatus of claim 7, wherein the device comprises a plurality of sensors,
the processing unit (15) is configured to determine an intersection point of the first distribution curve (501) and the second distribution curve (502), determine a curve segment in the first distribution curve (501) corresponding to a distance between the intersection point and the notch of the stator sample (11) as a first curve segment, determine a curve segment in the second distribution curve (502) corresponding to a distance between the intersection point and the notch of the stator sample (11) as a second curve segment, and determine a curve matched with the first curve segment and the second curve segment as the third distribution curve (503).
9. A motor slot electric field strength detection method (600), comprising:
acquiring the potential (601) of a plurality of induction rings (16) when two ends of a stator bar (12) are connected with a power supply (13), wherein the stator bar (12) is arranged in a groove formed by a stator sample (11), the structure of a notch on the stator sample (11) is the same as that of a stator notch in a motor to be detected, the grounding point of the stator sample (11) is grounded, a groove insulating layer (17) and an anti-corona layer (18) are sequentially wrapped on the stator bar (12), two ends of the stator bar (12) extend out of the notch of the stator sample (11), the stator bar (12) is the same as that of a stator winding in the motor to be detected, the stator sample (11) and the stator bar (12) are subjected to dip-coating treatment, the plurality of induction rings (16) are sleeved at one end of the stator bar (12), the plurality of induction rings (16) are positioned outside the groove of the stator sample (11), and the anti-corona layer (18) is positioned between the stator bar (16) and the stator bar (12);
an electric field intensity distribution (602) at the notch of the stator sample (11) is determined from the electric potentials of the plurality of induction loops (16).
10. The method of claim 9, wherein the step of determining the position of the substrate comprises,
the acquisition of the electric potential of a plurality of induction loops (16) when the two ends of the stator bar (12) are connected with a power supply (13) comprises:
respectively acquiring first potentials and second potentials of the plurality of induction rings (16), wherein the first potentials are potentials of the induction rings (16) when two ends of the stator bar (12) are connected with the positive electrode of the power supply (13) and the negative electrode of the power supply (13) is connected with the grounding point of the stator sample (11), and the second potentials are potentials of the induction rings (16) when two ends of the stator bar (12) are connected with the negative electrode of the power supply (13) and the positive electrode of the power supply (13) is connected with the grounding point of the stator sample (11);
-said determining the electric field intensity distribution at the notch of the stator sample (11) from the electric potentials of the plurality of induction loops (16), comprising: an electric field intensity distribution at the notch of the stator sample (11) is determined from the first and second electric potentials of the plurality of induction loops (16).
11. The method according to claim 10, wherein said determining the electric field intensity distribution at the notch of the stator sample (11) from the first and second electric potentials of the plurality of induction loops (16) comprises:
According to the capacitance value of the paint dipping layer (19) outside the stator bar (12) and the capacitance value of the electrometer (14), carrying out error correction on the first potential to obtain a third potential, and carrying out error correction on the second potential to obtain a fourth potential;
calculating the ratio of the difference between the third potentials of two adjacent induction loops (16) to the distance between the two induction loops (16) to obtain the first electric field intensity between the two induction loops (16);
calculating the ratio of the difference between the fourth potential of two adjacent induction loops (16) to the distance between the two induction loops (16) to obtain the second electric field intensity between the two induction loops (16);
determining a first distribution curve (501) according to each first electric field intensity, and determining a second distribution curve (502) according to each second electric field intensity, wherein the first distribution curve (501) and the second distribution curve (502) are used for indicating the electric field intensity of the surface of the stator bar (12) and change along with the distance from a notch of the stator sample (11);
a third distribution curve (503) for indicating an electric field intensity distribution at a notch of the stator sample (11) is determined from the first distribution curve (501) and the second distribution curve (502), wherein the third distribution curve (503) is used for indicating the electric field intensity of the surface of the stator bar (12) as a function of the distance to the notch of the stator sample (11).
12. The method according to claim 11, wherein the determining a third distribution curve (503) for indicating the electric field intensity distribution at the notch of the stator sample (11) from the first distribution curve (501) and the second distribution curve (502) comprises:
determining an intersection point of the first distribution curve (501) and the second distribution curve (502);
determining a curve segment in the first distribution curve (501) corresponding to a distance from the notch of the stator sample (11) being greater than a distance between the intersection point and the notch of the stator sample (11) as a first curve segment;
determining a curve segment of the second distribution curve (502), wherein the distance between the curve segment and a notch of the stator sample (11) is smaller than the distance between the intersection point and the notch of the stator sample (11);
-determining a curve matching the first curve segment and the second curve segment as the third distribution curve (503).
13. An electronic device (900), comprising: -a processor (902), a communication interface (904), a memory (906) and a communication bus (908), said processor (902), said memory (906) and said communication interface (904) completing communication with each other through said communication bus (908);
The memory (906) is configured to store at least one executable instruction, where the executable instruction causes the processor (902) to perform operations corresponding to the motor slot electric field intensity detection method according to any one of claims 9-12.
14. A computer readable storage medium having stored thereon computer instructions which, when executed by a processor, cause the processor to perform the method of any of claims 9-12.
15. A computer program comprising computer-executable instructions which, when executed, cause at least one processor to perform the method of any one of claims 9-12.
16. A computer program product tangibly stored on a computer-readable medium and comprising computer-executable instructions that, when executed, cause at least one processor to perform the method of any one of claims 9-12.
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