CN112491228B - Method for detecting key magnetic pole causing stator low-frequency vibration based on vibration waveform - Google Patents
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Abstract
The invention relates to a method for detecting a key magnetic pole causing low-frequency vibration of a stator based on vibration waveforms, and belongs to the technical field of hydraulic generators. The method comprises the steps of firstly collecting a stator low-frequency vibration waveform data value, numbering magnetic poles according to the rotation direction of a generator set, enabling vibration waveform recording initial data to correspond to a magnetic pole No. 1, then calculating acceleration characteristic values corresponding to air gaps of the magnetic poles according to a waveform acceleration calculation formula, finding out key magnetic poles influencing vibration amplitude, adjusting the air gaps of the key magnetic poles to obtain correspondingly changed acceleration measurement, calculating corresponding waveforms through reverse direction, and finally finding out an air gap adjustment scheme that vibration waveform amplitude reaches a target value, so that low-frequency vibration of a generator stator is effectively reduced, and working efficiency is greatly improved.
Description
Technical Field
The invention belongs to the technical field of hydraulic generators, and particularly relates to a method for detecting a key magnetic pole causing low-frequency vibration of a stator based on vibration waveforms.
Background
In recent years, with the operation of domestic huge hydroelectric generating sets, tests show that both stator bases and iron cores of hydroelectric generating sets have the problem of low-frequency vibration in the operation process. Generally, low-frequency vibration is qualitatively considered to be caused by insufficient roundness or eccentricity of a stator and a rotor, but how to adopt effective measures to control the low-frequency vibration is not a quantitative technical solution in the prior art, and the main measures for treating the low-frequency vibration of the stator are as follows: the rotor is hung outside the machine pit, the magnetic poles are disassembled, the roundness and the eccentricity of the rotor are improved by adjusting the magnetic pole gaskets, the magnetic poles of the rotor are generally required to be adjusted one by one, and the rotor is not only blind but also large in adjustment workload, time-consuming, labor-consuming and low in working efficiency. In addition, practice proves that the problem of low-frequency vibration of the stator cannot be effectively solved only by improving the static roundness of the rotor, and the low-frequency vibration of the stator is difficult to achieve the expected effect even if the low-frequency vibration is increased due to the influence of factors such as uneven thermal expansion of a magnetic yoke of the rotor, virtual tightening of magnetic pole keys, change of a rotation center of the rotor, uneven dynamic air gap after the rotor rotates and the like. Therefore, it is necessary to develop a method of detecting the critical magnetic poles causing the low frequency vibration of the stator.
Disclosure of Invention
The invention aims to solve the defects in the prior art, provides a method for accurately finding key magnetic poles influencing the low-frequency vibration of a stator of a giant hydraulic generator based on vibration waveform change, and improves the treatment efficiency and effect of the overproof low-frequency vibration of the stator.
In order to realize the purpose, the technical scheme adopted by the invention is as follows:
the method for detecting the key magnetic pole causing the low-frequency vibration of the stator based on the vibration waveform comprises the following steps:
collecting a low-frequency vibration waveform data value of a stator of a hydraulic generator, numbering magnetic poles according to the rotation direction of the generator set, and enabling vibration waveform recording initial data to correspond to the magnetic pole No. 1;
step (2), calculating the acceleration corresponding to each magnetic pole air gap according to the vibration displacement value in the acquired vibration waveform;
step (3), searching for magnetic poles which are continuously positive or continuously negative in acceleration amount and are connected with each other to serve as key magnetic pole regions influencing the vibration amplitude;
selecting a target magnetic pole from the key magnetic pole area, adjusting the air gap of the magnetic pole, obtaining a corresponding acceleration characteristic value after the air gap is adjusted through the relationship between the air gap change and the acceleration characteristic value change obtained through the previous adjustment experience, and reversely calculating a corresponding waveform;
and (5) adjusting the air gap variation until the calculated vibration waveform amplitude (difference between the maximum value and the minimum value) reaches a target value, wherein the air gap variation is a target adjustment scheme, and then adjusting the magnetic pole air gap according to the scheme so as to reduce the low-frequency vibration of the stator.
Further, it is preferable that the specific method of the step (2) is:
taking displacement values of vibration waveforms in one period, marking as A1, A2, A3 \8230, 8230and the like;
then calculating the difference of the vibration waveform displacement values of two adjacent points in the vibration waveform to obtain a waveform difference value which is marked as B1, B2, B3 \8230, namely B1= A2-A1, B2= A3-A2, and the like;
then calculating the difference between the waveform differences of two adjacent points to obtain the speed difference value which is marked as C1, C2, C3 \8230, 8230, namely C1= B2-B1, C2= B3-B2, and the like; the difference in velocity is the acceleration measurement.
Further, it is preferable that the average value of the acceleration amounts corresponding to the magnetic poles is used as the characteristic value a' of the acceleration corresponding to the magnetic pole,
n is the number of acceleration corresponding to 1 magnetic pole, and n = the number of measurement points per magnetic pole in one period.
Further, it is preferable to use a magnetic pole of a past magnetic poleThe air gap adjustment data and the result data are calculated and analyzed to obtain the relationship between the air gap adjustment quantity delta L of the unit and the acceleration characteristic value variation delta a
k is an acceleration change coefficient which can be determined according to the change of the acceleration characteristic value after the magnetic pole air gap is adjusted in each time; delta L is the adjustment amount of the air gap of the key magnetic pole; Δ a' is the acceleration characteristic value variation.
Further, it is preferable that the specific method of step (4) is:
selecting 1 magnetic pole positioned in the middle of the key magnetic pole area as a target magnetic pole in the key magnetic pole area with the acceleration characteristic value a' continuously positive or continuously negative; when target pole air gap changes Δ L 1 Acceleration characteristic value variation amount Δ L 1 ＝kΔa 1 ' after adjustment, adding delta a to the n acceleration values corresponding to the magnetic pole 1 '，ci＝Ci+Δa 1 ', i = j1+ j2+ ·+ jn, resulting in an adjusted acceleration, denoted as c1, c2, c3.... Ci.... C256;
performing accumulation calculation (opposite to difference calculation) on the acceleration of each point after adjustment to obtain an adjusted speed quantity, wherein b2= b1+ c2, b3= b2+ c3.. So on;
and accumulating and calculating the speed of each point after adjustment to obtain the adjusted displacement (waveform), wherein a2= a1+ b2, a3= a2+ b3.
In the step (3) of the invention, the number of the magnetic poles of the key magnetic pole area is determined by the vibration condition, and the number is not fixed.
The main reason of the stator low-frequency vibration is caused by the periodic change of the magnetic tension, and according to Newton's second law F = ma, under the condition that the mass m is not changed, the amplitude of the low-frequency vibration is related to the change of the acceleration a. According to
The vibration displacement x can be differentiated twice with respect to time t to obtain a vibration acceleration amount a. Period of vibration of stator frame
And n is the unit rotating speed, and when n =125r/min, T =0.48s.
The invention calculates the acceleration change of the installation position of the sensor through the waveform, obtains the influence degree of the dynamic air gap of the magnetic pole on the acceleration according to the corresponding relation between the acceleration period and the air gap of the magnetic pole of the rotor, and finds out the key magnetic pole for reducing the vibration amplitude.
Through calculation and analysis of the air gap adjustment data and the result data of the previous magnetic poles, the relation between the air gap adjustment quantity delta L of the unit and the acceleration characteristic value variation delta a' can be obtained
k is an acceleration change coefficient, different types of generator sets have different k values, and the k value can be determined according to the change of the acceleration characteristic value after the magnetic pole air gap is adjusted in the past; delta L is the adjustment amount of the air gap of the key magnetic pole; Δ a' is the acceleration characteristic value variation.
Adjusting the corresponding acceleration value of the key magnetic pole, obtaining a vibration waveform through inverse calculation according to the adjusted acceleration distribution, adjusting the magnitude of the acceleration value of the magnetic pole and the number of the magnetic poles until the peak value of the vibration peak reaches an expected target, and obtaining the air gap adjustment quantity of each magnetic pole according to the relation delta L = k delta a' between the air gap adjustment quantity and the acceleration characteristic value variation quantity.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a method for detecting a key magnetic pole causing low-frequency vibration of a stator based on vibration waveforms, which comprises the following steps: collecting data values of low-frequency vibration waveforms of the stator, numbering the magnetic poles according to the rotation direction of the generator set, enabling vibration waveform recording initial data to correspond to a magnetic pole No. 1, calculating acceleration characteristic values corresponding to air gaps of the magnetic poles according to a waveform acceleration calculation formula, finding out key magnetic pole regions (usually, the acceleration characteristic values are continuously positive or continuously negative magnetic poles) influencing vibration amplitude values, selecting 1 magnetic pole located in the middle of the key magnetic pole regions, adjusting the air gaps of the magnetic poles, obtaining corresponding acceleration characteristic values after air gap adjustment through the relation between air gap changes and acceleration characteristic value changes obtained through previous adjustment experience, and reversely calculating corresponding waveforms. Finding out the corresponding magnetic pole air gap adjustment quantity when the vibration waveform amplitude (difference between the maximum value and the minimum value) reaches the target value, namely the target adjustment scheme. Compared with the prior art for improving the static roundness of the rotor, the invention does not need to consider the influence of factors such as uneven thermal expansion of the rotor magnetic yoke and the like, and can effectively reduce the low-frequency vibration of the generator stator. According to the existing static rotor circle adjusting technology, the rotor is lifted out of a machine pit every time to measure and adjust the roundness, the construction period is at least 80 days, the rotor does not need to be lifted out, the magnetic pole adjustment time is 1 time in the machine pit and is at most 8 days, and the efficiency is at least 10 times that of the prior art.
Drawings
FIG. 1 is a horizontal vibration waveform of a stator frame;
FIG. 2 is a graph of acceleration distribution calculated from a waveform;
FIG. 3 is a graph of acceleration corresponding to a magnetic pole;
FIG. 4 is a graph of acceleration characteristic values corresponding to each magnetic pole;
FIG. 5 is a diagram of the waveform prediction after the adjustment of the pole air gap;
fig. 6 is a horizontal vibration waveform diagram of the stator frame after the actual magnetic pole air gap is adjusted.
Detailed Description
The present invention will be described in further detail with reference to examples.
It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. Those skilled in the art will recognize that the specific techniques or conditions, not specified in the examples, are according to the techniques or conditions described in the literature of the art or according to the product specification. The materials or equipment used are not indicated by manufacturers, and all are conventional products available by purchase.
Example 1
The method for detecting the key magnetic pole causing the stator to vibrate at low frequency based on the vibration waveform comprises the following steps:
collecting a low-frequency vibration waveform data value of a stator of a hydraulic generator, numbering magnetic poles according to the rotation direction of the generator set, and enabling vibration waveform recording initial data to correspond to the magnetic pole No. 1;
step (2), calculating the acceleration corresponding to each magnetic pole air gap according to the vibration displacement value in the acquired vibration waveform;
step (3), searching for a connected magnetic pole with continuous positive or continuous negative acceleration as a key magnetic pole area influencing the vibration amplitude;
step (4), selecting a target magnetic pole from the key magnetic pole area, adjusting the air gap of the magnetic pole, obtaining the corresponding acceleration characteristic value after the air gap is adjusted through the relationship between the air gap change and the acceleration characteristic value change, and reversely calculating the corresponding waveform;
and (5) adjusting the air gap variable quantity until the calculated vibration waveform amplitude reaches a target value, wherein the air gap variable quantity is a target adjustment scheme, and then adjusting the magnetic pole air gap according to the scheme.
Example 2
The method for detecting the key magnetic pole causing the low-frequency vibration of the stator based on the vibration waveform comprises the following steps:
collecting a low-frequency vibration waveform data value of a stator of a hydraulic generator, numbering magnetic poles according to the rotation direction of the generator set, and enabling vibration waveform recording initial data to correspond to the magnetic pole No. 1;
step (2), calculating the acceleration corresponding to each magnetic pole air gap according to the vibration displacement value in the acquired vibration waveform;
step (3), searching for a connected magnetic pole with continuous positive or continuous negative acceleration as a key magnetic pole area influencing the vibration amplitude;
step (4), selecting a target magnetic pole from the key magnetic pole area, adjusting the air gap of the magnetic pole, obtaining the corresponding acceleration characteristic value after the air gap is adjusted through the relationship between the air gap change and the acceleration characteristic value change, and reversely calculating the corresponding waveform;
and (5) adjusting the air gap variation until the calculated vibration waveform amplitude reaches a target value, wherein the air gap variation is a target adjustment scheme, and then adjusting the magnetic pole air gap according to the scheme.
The specific method of the step (2) is as follows:
taking the displacement values of the vibration waveform in one period as A1, A2 and A3 \8230;
then calculating the difference of the displacement values of the vibration waveforms of two adjacent points in the vibration waveforms to obtain waveform difference values, namely B1, B2, B3, 8230, namely B1= A2-A1, B2= A3-A2, and the like;
then calculating the difference between the waveform differences of two adjacent points to obtain the speed difference value which is marked as C1, C2, C3 \8230, 8230, namely C1= B2-B1, C2= B3-B2, and the like; the difference in velocity is an acceleration measure.
Taking the average value of the acceleration corresponding to the magnetic pole as the characteristic value a' of the acceleration corresponding to the magnetic pole,
n is the number of acceleration corresponding to 1 magnetic pole, and n = the number of measurement points per magnetic pole in one period.
Relation between air gap adjustment quantity delta L of unit and acceleration characteristic value variation delta a
k is an acceleration change coefficient; delta L is the adjustment amount of the air gap of the key magnetic pole; Δ a' is the acceleration characteristic value variation.
The specific method of the step (4) is as follows:
selecting 1 magnetic pole positioned in the middle of the key magnetic pole area as a target magnetic pole in the key magnetic pole area with the acceleration characteristic value a' continuously positive or continuously negative; when the target pole air gap changes by Δ L 1 Acceleration characteristic value variation Δ L 1 ＝kΔa 1 ' after adjustment, adding delta a to the n acceleration values corresponding to the magnetic pole 1 '，ci＝Ci+Δa 1 ', i = j1+ j2+ ·+ jn, resulting in an adjusted acceleration, denoted as c1, c2, c3.... Ci.... C256;
performing accumulation calculation on the accelerated speeds of the adjusted points to obtain the adjusted speed quantity, wherein b2= b1+ c2, b3= b2+ c3.. So on;
and performing accumulation calculation on the speed of each point after adjustment to obtain the adjusted displacement, wherein a2= a1+ b2, a3= a2+ b3.
Examples of the applications
The rotating speed of a generator of a certain power plant is 125r/min, 48 magnetic poles are arranged, displacement type vibration sensors are arranged in the + X direction and the-Y direction respectively and used for detecting horizontal vibration displacement signals (256 measured points in each period) in the + X direction and the-Y direction of a stator frame and sending the signals to a water turbine stability detection and analysis system TN8000, the peak value (the maximum value-the minimum value in one period) of the low-frequency vibration peak of the generator of the power plant is 143 mu m, the time of the initial measured point of vibration in the + X direction is swept in the + X direction corresponding to the magnetic pole No. 1 of a rotor, and the peak value of the low-frequency vibration peak is reduced to 48 mu m after treatment.
(1) Vibration data acquisition
a. The horizontal vibration waveform of the stator frame appears according to a periodic rule, and the horizontal vibration waveform data of the stator of the unit under no-load or load working conditions is collected through a TN8000 detection and analysis system of the water turbine, as shown in figure 1, wherein Y is a vibration displacement value, and X is a periodic value. The vibration waveform values in one period of 0.48s are taken, such as A1 and A2.. A256 in Table 1, and the total number of points is 256.
TABLE 1
| Serial number | Vibration waveform value | Difference in waveform | Difference in |
| 1 | A'256＝-4.7 | B'256＝-1.8 | C'256＝-1.7 |
| 2 | A1＝-6 | B1＝-1.3 | C1＝0.5 |
| 3 | A2＝-9.1 | B2＝-3.1 | C2＝-1.8 |
| 4 | A3＝-10.8 | B3＝-1.7 | C3＝1.4 |
| 5 | A4＝-11.4 | B4＝-0.6 | C4＝1.1 |
| 6 | A5＝-10.3 | B5＝1.1 | C5＝1.7 |
| 7 | A6＝-11.2 | B6＝-0.9 | C6＝-2 |
| 8 | A7＝-12.9 | B7＝-1.7 | C7＝-0.8 |
| … | … | … | … |
| 256 | A256＝-4.3 | B256＝-2 | C256＝-1.1 |
Note: a'256 is the value at the 256 th point in the cycle of the vibration waveform. B'256 is the waveform difference value at the 256 th point of the previous period; c'256 is the speed difference at the 256 th point of the previous period;
(2) Calculating acceleration distribution from vibration waveform
b. The waveform difference (velocity) values B1, B2 \8230andb 256 are obtained by subtracting two adjacent points from the acquired waveform data in one period, as shown in the waveform difference part of table 1, wherein B1= A2-A1, B2= A3-A2, and so on, and the result is the velocity value shown in fig. 2.
c. Using the calculated waveform difference data in one period, the difference between two adjacent points is calculated to obtain the velocity difference (acceleration) values C1, C2 \8230c256, as shown in table 1, wherein C1= B2-B1, C2= B3-B2, and so on, and the result is shown in the acceleration value in fig. 2.
d. The 256 acceleration values were divided equally into 48, corresponding to 48 poles of the rotor, each corresponding to 5.3 points. In order to divide the measuring points equally, 3 magnetic poles are taken as a group, and every two magnetic poles share 1 point, as shown in FIG. 3,3 magnetic poles correspond to 16 acceleration values, and 48 magnetic poles divide 256 acceleration values equally.
e. Taking the average value of 6 acceleration measurements corresponding to the magnetic pole as the acceleration characteristic value corresponding to the magnetic pole, #1 magnetic pole acceleration characteristic value
# 2 magnetic-pole acceleration characteristic value
# 3 characteristic value of magnetic acceleration
# 4 magnetic pole acceleration eigenvalue
And so on to obtain the acceleration characteristic value corresponding to 48 magnetic poles, as shown in fig. 4.
f. According to F = ma, the change of the acceleration reflects the change of the received resultant force, so that the change of the magnetic pole air gap is indirectly reflected, and similarly, the adjustment of the magnetic pole air gap causes the change of the acceleration, for example, the air gap is reduced to increase the acceleration value. As shown in fig. 4, there are 4 critical magnetic pole regions (# 17- #20 and #36- #39, the magnetic poles are continuously positive, and #25- #27 and #36- #39, the magnetic poles are continuously negative), and the magnetic poles #19, #26, #37 and #44 are respectively selected from the middle positions of the 4 critical magnetic pole regions to perform air gap adjustment, so as to reduce the amplitude of the stator frame vibration waveform.
(3) The waveform is reversely calculated from the acceleration distribution.
g. And adjusting the air gaps of the partial magnetic poles to obtain new acceleration distribution c1, c2, c3 and c4.
TABLE 2
| Serial number | Difference in velocity | Difference in waveform | |
| 1 | c'256＝0.3 | b'256＝-1.2 | a’256＝-5 |
| 2 | c1＝-0.5 | b1＝-1.7 | a1＝-6.7 |
| 3 | c2＝-2.2 | b2＝-3.9 | a2＝-10.6 |
| 4 | c3＝1.8 | b3＝-2.1 | a3＝-12.7 |
| 5 | c4＝0.3 | b4＝-1.8 | a4＝-14.5 |
| 6 | C5＝2.5 | b5＝0.7 | a5＝-13.8 |
| … | … | … | … |
| 256 | c256＝0.5 | b256＝1.1 | a256＝-2 |
Note: c'256 is the 256 th point speed difference in the previous cycle after adjustment. b'256 is the waveform difference value at the 256 th point of the last period after adjustment; a'256 is the waveform value at the 256 th point of the previous period after adjustment.
h. The acceleration of each point after adjustment is accumulated (as opposed to difference calculation) to obtain the adjusted speed, b1= b'256+ c1, b2= b1+ c2, b3= b2+ c3, and so on.
i. The adjusted speed of each point is accumulated to obtain the adjusted displacement (waveform), a1= a'256+ b1, a2= a1+ b2, a3= a2+ b3, and so on.
(4) Rotor roundness adjustment scheme and anticipation
j. According to the corresponding acceleration change rule of the unit of the embodiment after the previous air gap adjustment, the relationship between the air gap change amount and the acceleration characteristic value change amount of the unit is obtained as follows: Δ L ≈ -1.5 Δ a'.
k. After 4 magnetic poles are adjusted, the waveform is predicted as shown in fig. 5, and the peak value of the vibration is about 40 μm and reaches the target value. Obtaining an adjustment scheme: the air gap of the #19 magnetic pole is increased by 0.9mm, the air gap of the #26 magnetic pole is reduced by 1.5mm, the air gap of the #37 magnetic pole is increased by 1.5mm, and the air gap of the #44 magnetic pole is reduced by 1.5mm.
In this row, after the key magnetic pole is determined according to the method of the present invention, only the #26 magnetic pole air gap (reduced by 1.9 mm) and the #44 magnetic pole air gap (reduced by 1.5 mm) are adjusted, the horizontal vibration peak value of the generator stator has been reduced to 48 μm, the vibration waveform is as shown in fig. 6, and the actual vibration amplitude is not much different from the predicted vibration amplitude.
The method is based on vibration waveform analysis and has the advantages of high efficiency and good effect of stator low-frequency vibration treatment. Compared with the prior art for improving the static roundness of the rotor, the method has the advantages that the influence of factors such as uneven thermal expansion of a rotor magnetic yoke does not need to be considered, and the low-frequency vibration of the stator of the generator can be effectively reduced. According to the existing static rotor circle adjusting technology, the rotor is lifted out of a machine pit each time to measure and adjust the roundness, the construction period is at least 80 days, the rotor does not need to be lifted out, the magnetic pole adjustment time is 1 time in the machine pit for at most 8 days, and the efficiency is at least 10 times that of the prior art.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (1)
1. The method for detecting the key magnetic pole causing the low-frequency vibration of the stator based on the vibration waveform is characterized by comprising the following steps of:
collecting a low-frequency vibration waveform data value of a stator of a hydraulic generator, numbering magnetic poles according to the rotation direction of the generator set, and enabling vibration waveform recording initial data to correspond to the magnetic pole No. 1;
step (2), calculating the acceleration corresponding to each magnetic pole air gap according to the vibration displacement value in the acquired vibration waveform;
step (3), searching for a connected magnetic pole with continuous positive or continuous negative acceleration as a key magnetic pole area influencing the vibration amplitude;
selecting a target magnetic pole from the key magnetic pole area, adjusting the air gap of the magnetic pole, obtaining a corresponding acceleration characteristic value after the air gap is adjusted through the relation between the change of the air gap and the change of the acceleration characteristic value, and reversely calculating a corresponding waveform;
step (5), adjusting the air gap variable quantity until the calculated vibration waveform amplitude reaches a target value, wherein the air gap variable quantity is a target adjustment scheme, and then adjusting the magnetic pole air gap according to the scheme;
the specific method of the step (2) comprises the following steps:
taking the displacement values of the vibration waveform in one period as A1, A2 and A3 \8230;
then calculating the difference of the vibration waveform displacement values of two adjacent points in the vibration waveform to obtain a waveform difference value which is marked as B1, B2, B3 \8230, namely B1= A2-A1, B2= A3-A2, and the like;
then calculating the difference between the waveform differences of two adjacent points to obtain the speed difference value which is marked as C1, C2, C3 \8230, 8230, namely C1= B2-B1, C2= B3-B2, and the like; the speed difference is an acceleration measurement;
taking the average value of the acceleration corresponding to the magnetic pole as the characteristic value a' of the acceleration corresponding to the magnetic pole,
n is the corresponding acceleration amount number of 1 magnetic pole, and n = the number of measurement points/magnetic pole number in one period;
relation between air gap adjustment quantity delta L of unit and delta a' of variation of acceleration characteristic value
k is an acceleration change coefficient; delta L is the adjustment amount of the air gap of the key magnetic pole; delta a' is the variation of the acceleration characteristic value;
the specific method of the step (4) is as follows:
selecting 1 magnetic pole positioned in the middle of the key magnetic pole area as a target magnetic pole in the key magnetic pole area with the acceleration characteristic value a' continuously positive or continuously negative; when the target pole air gap changes by Δ L 1 Acceleration characteristic value variation Δ L 1 ＝kΔa 1 ' after adjustment, adding delta a to the n acceleration values corresponding to the magnetic pole 1 '，ci＝Ci+Δa 1 ', i = j1+ j2+.. + jn, obtaining an adjusted acceleration, which is denoted as c1, c2, c3.... Ci.... C256;
performing accumulation calculation on the accelerated speeds of the points after adjustment to obtain the speed amount after adjustment, wherein b2= b1+ c2, b3= b2+ c3.. The other way round;
and performing accumulation calculation on the speed of each point after adjustment to obtain the adjusted displacement, wherein a2= a1+ b2, a3= a2+ b3.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5662051A (en) * | 1979-10-24 | 1981-05-27 | Toshiba Corp | Evaluation for adhesive property of secondary conductor of cage rotor |
| WO1981002370A1 (en) * | 1980-02-04 | 1981-08-20 | Kirby James N Pty Ltd | Method and apparatus for air gap setting |
| JPH08214512A (en) * | 1995-02-01 | 1996-08-20 | Toshiba Corp | Method and device for adjusting balance of rotating machine |
| CN101608911A (en) * | 2008-06-19 | 2009-12-23 | 三菱电机株式会社 | Air gap eccentric centre detection device, method, method of adjustment and monocyclic-start induction motor |
| CN103595201A (en) * | 2013-11-12 | 2014-02-19 | 周建设 | Method for adjusting air gap of high-voltage motor |
| CN103913272A (en) * | 2014-04-03 | 2014-07-09 | 华北电力大学 | Quantitative diagnosis method for rotor mass unbalance fault of steam turbine generator unit |
| CN108429406A (en) * | 2018-02-24 | 2018-08-21 | 南方电网调峰调频发电有限公司 | A method of analysis stator core abnormal vibrations are monitored by air gap |
| CN110635635A (en) * | 2019-06-27 | 2019-12-31 | 华能澜沧江水电股份有限公司 | Method for reducing low-frequency vibration of generator stator based on air gap characteristic value |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102425561B (en) * | 2011-12-05 | 2014-04-30 | 北京中科科仪股份有限公司 | Dynamic balance method for magnetic suspension molecular pump |
| CN103867475B (en) * | 2012-12-18 | 2016-10-05 | 上海宝钢工业技术服务有限公司 | Birotor axial flow blower on-line operation condition detection method |
| CN105277348B (en) * | 2015-10-13 | 2018-08-17 | 国家电网公司 | A kind of hydrogenerator prototype stator core-engine base system frequency measurement method |
| US10691211B2 (en) * | 2018-09-28 | 2020-06-23 | Apple Inc. | Button providing force sensing and/or haptic output |
-
2020
- 2020-11-06 CN CN202011232832.8A patent/CN112491228B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5662051A (en) * | 1979-10-24 | 1981-05-27 | Toshiba Corp | Evaluation for adhesive property of secondary conductor of cage rotor |
| WO1981002370A1 (en) * | 1980-02-04 | 1981-08-20 | Kirby James N Pty Ltd | Method and apparatus for air gap setting |
| JPH08214512A (en) * | 1995-02-01 | 1996-08-20 | Toshiba Corp | Method and device for adjusting balance of rotating machine |
| CN101608911A (en) * | 2008-06-19 | 2009-12-23 | 三菱电机株式会社 | Air gap eccentric centre detection device, method, method of adjustment and monocyclic-start induction motor |
| CN103595201A (en) * | 2013-11-12 | 2014-02-19 | 周建设 | Method for adjusting air gap of high-voltage motor |
| CN103913272A (en) * | 2014-04-03 | 2014-07-09 | 华北电力大学 | Quantitative diagnosis method for rotor mass unbalance fault of steam turbine generator unit |
| CN108429406A (en) * | 2018-02-24 | 2018-08-21 | 南方电网调峰调频发电有限公司 | A method of analysis stator core abnormal vibrations are monitored by air gap |
| CN110635635A (en) * | 2019-06-27 | 2019-12-31 | 华能澜沧江水电股份有限公司 | Method for reducing low-frequency vibration of generator stator based on air gap characteristic value |
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