LU504058B1 - Stator insulation level detection method of gas turbine generator - Google Patents
Stator insulation level detection method of gas turbine generator Download PDFInfo
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- LU504058B1 LU504058B1 LU504058A LU504058A LU504058B1 LU 504058 B1 LU504058 B1 LU 504058B1 LU 504058 A LU504058 A LU 504058A LU 504058 A LU504058 A LU 504058A LU 504058 B1 LU504058 B1 LU 504058B1
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- 238000009413 insulation Methods 0.000 title claims abstract description 156
- 238000001514 detection method Methods 0.000 title claims abstract description 41
- 238000004804 winding Methods 0.000 claims abstract description 63
- 230000010287 polarization Effects 0.000 claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 36
- 230000036961 partial effect Effects 0.000 claims abstract description 19
- 230000002829 reductive effect Effects 0.000 claims abstract description 10
- 230000028161 membrane depolarization Effects 0.000 claims description 37
- 238000012360 testing method Methods 0.000 claims description 21
- 230000008859 change Effects 0.000 claims description 11
- 230000007423 decrease Effects 0.000 claims description 7
- 238000005316 response function Methods 0.000 claims description 7
- 238000005259 measurement Methods 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 230000032683 aging Effects 0.000 description 5
- 230000035882 stress Effects 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000002845 discoloration Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000002301 combined effect Effects 0.000 description 2
- 230000032798 delamination Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006353 environmental stress Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/34—Testing dynamo-electric machines
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Tests Of Circuit Breakers, Generators, And Electric Motors (AREA)
Abstract
The invention discloses a method for detecting the insulation level of a stator of a generator of a gas generating set, which comprises the following steps of: Carry out direct current polarization current detection on that stator insulation to be detected and jud whether the insulation level of the winding is reduced or not; When the insulation level of the stator winding to be detected is reduced, the insulation of the stator to be detected shall be subject to on-line partial discharge detection. According to the method, whether the insulation level of the winding is reduced or not can be accurately judged, so that the insulation level of the stator of the generator of the gas generator set is judged, possible mandatory fault power failure is prevented, and safe and stable operation of a power plant is guaranteed.
Description
Stator insulation level detection method of gas turbine generator 594058
The invention relates to the technical field of generator stator insulation level detection, in particular to a method for detecting the insulation level of a generator stator of a gas turbine generator set.
Background technology
During the daily operation of a generator set, a failure of the generator set due to a reduction in the insulation level of the generator stator components of a gas-fired unit can result in significant time and economic costs. The reliable operation of rotating machinery depends to a large extent on the integrity of its stator winding insulation, which is subject to deterioration under the combined effects of thermal, electrical, mechanical and environmental stresses.
Therefore, it is necessary to regularly detect the insulation level of the generator stator to assess its insulation condition. The insulation level detection is helpful for the power plant to formulate a planned maintenance and repair schedule, so that the generator stator can be repaired in time to prevent possible mandatory power outages and ensure the safe and stable operation of the power plant.
DC test is an important insulation detection method for rotating machinery system. For decades, DC testing has been widely used in the energy industry to ensure the condition of the insulation system of new and in-service equipment, and is recognized as an effective way to detect faults such as component cracks, winding contamination and moisture.
The purpose of this section is to summarize some aspects of embodiments of the invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section and in the abstract and title of this application to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions are not intended to limit the scope of the invention. [0005] The present invention is proposed in view of the above and/or the problems existing in the existing methods for detecting the insulation level of the stator of a gas turbine generator.
Therefore, the problem to be solved by the present invention is how to provide a method for detecting the insulation level of a stator of a gas turbine generator.
In order to solve the technical problem, the invention provides the following technical scheme: the method for detecting the insulation level of the stator of the generator of the gas unit comprises the following steps of: carrying out appearance inspection on the stator insulation to judge whether the appearance is stained or not; Carry out direct current polarization current detection on that stator insulation to be detected and jud whether the insulation level of thé/504058 winding is reduced or not; When the insulation level of the stator winding to be detected is reduced, the insulation of the stator to be detected shall be subject to on-line partial discharge detection.
As a preferable scheme of that method for detect the insulation level of the generator stator of the gas turbine generator set, the method for detecting the insulation level of the stator to be detect through direct current polarization current comprises the following steps of: Carry out depolarization current detection on a detected stator win sample to obtain a depolarization current change value; The polarization and depolarization detection currents were normalized to the standard volume temperature. Drawing and analyzing the change of the measured current to judge the insulation level of the detected sample; According to the relative distance between the polarization current curve and the depolarization current curve obtained from the insulation test of each phase winding, it is determined whether there is a decline in the insulation level of the winding.
As a preferable scheme of the method for detecting the insulation level of the generator stator of the gas turbine generator set, the polarization and depolarization detection current is normalized to the standard capacity temperature by adopting the following formula:
BST
Where, C is the capacitance value of generator stator insulation winding, and Kt is the temperature coefficient of insulation resistance at temperaturet.
As a preferable scheme of that method for detect the insulation level of the stator of the generator of the gas unit,
Wherein, the following formula is adopted when the polarization current of the detected stator winding sample is measured:
LH 2 [ad . ;
Where f (t) is the dielectric response function, f (t) = At”, Cois the vacuum capacity, is the insulation conductivity, Ileakt) represents the insulation leakage current, and IleakT) represents the insulation leakage current.
As a preferable scheme of the method for detecting the insulation level of the generator stator of the gas turbine generator set, the method comprises the following steps of: idise(t) = VCO(6(t)+f(t)-f(t+te))
Where, tc is the time for which the voltage is applied to the insulating layer, and since f (t) is a monotonically decreasing function of time, f (t + tc) = 0 when t (TS21) tends to infinity under ideal conditions, the above equation is: LUS04058 idisc(t)= VCO(6(t)+f(t))
Where f (t) is the dielectric response function, f (t) = At-n, and CO is the vacuum capacity.
As a preferable scheme of the method for detecting the insulation level of the generator stator of the gas turbine generator set, the distance between polarization and depolarization detection current curves at the same time point 1s calculated by the following formula:
Dei, 0) fl) = VO i)
Where f (t) is the dielectric response function, f (t) = At-n, and COis the vacuum capacity.
As a preferable scheme of the method for detecting the insulation level of the generator stator of the gas generating set, when the insulation of the stator to be detected is subjected to on-line partial discharge detection, partial discharge parameters include maximum discharge quantity, initial discharge quantity, discharge times, pulse height, phase distribution map and the like.
As a preferable scheme of the method for detecting the insulation level of the stator of the generator of the gas generator set, when the vertical distance between a polarization current curve and a depolarization current curve is less than 0.1 cm at the same time, the insulation level of the stator is good
As a preferable scheme of the method for detecting the stator insulation level of the gas turbine generator, when the vertical distance between a polarization current curve and a depolarization current curve is between 0.1 cm and 0.3 cm at the same time, the stator insulation level is reduced
As a preferable scheme of the method for detecting the stator insulation level of the generator of the gas generator set, when the vertical distance between a polarization current curve and a depolarization current curve is more than 0.3cm at the same time, the stator insulation level is poor.
The method disclose by that invention has the beneficial effects that whet the insulation level of the winding is reduced or not can be accurately judged, so that the insulation level of the generator stator of the gas turbine generator set is jud, the possible forced fault power failure is prevented, and the safe and stable operation of a power plant is guaranteed.
Description of attached figures
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to these drawings without creative labor. Among
Fig. 1 is an insulation detection current curve of the stator winding 1 of the gas turbine generatb}#504058 stator insulation level detection method.
Fig. 2 is an insulation detection current curve of the stator winding 2 of the gas turbine generator stator insulation level detection method.
Fig. 3 is an insulation detection current curve of the stator winding 3 of the gas turbine generator stator insulation level detection method.
Fig. 4 is a diagram showing the relationship between the distance D and the resistance Rd in the method for detecting the insulation level of the stator of the gas turbine generator. Fig. 5 is a partial discharge detection diagram of the end of the winding 2 according to the stator insulation level detection method of the gas turbine generator.
In order that the above objects, features and advantages of the present invention may be more readily understood, a detailed description of the preferred embodiments of the present invention will be described in conjunction with the accompanying drawings.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced otherwise than as described herein, and similar modifications may be made by those skilled in the art without departing from the spirit of the invention, which is therefore not limited to the specific embodiments disclosed below.
Second, the reference herein to "one embodiment" or "an embodiment" refers to a particular feature, structure, or characteristic that may be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Example 1
Referring to fig. 1 to fig. 4, a first embodiment of the present invention provides a method for detecting an insulation level of a stator of a gas turbine generator. The method for detecting an insulation level of a stator of a gas turbine generator comprises the following steps:
Check the appearance of the stator insulation to determine whether there is any stain on the appearance. Appearance inspection is mainly to check the degree of dust and oil on the stator insulation layer, discoloration and shedding of covering paint, insulation damage, insulation overheat discoloration, leakage traces, etc.
Carry out direct current polarization current detection on that stator insulation to be detected; In a
DC insulation test, the three components of the charging current of the measured medium are the capacitive charging current, the dielectric absorption (polarization) current, and the leakagd/504058 (conduction) current.
Capacitive current is the component due to the capacitance of the winding to ground. The capacitive current decays to zero in seconds after the voltage is applied, and the time constant 5 depends on the instrument resistance in series with the winding. Capacitive charging is a reversible energy that can be stored and is usually not considered when testing the state of an insulation system. The response of the sink current to the step voltage is similar to that of the capacitor current, but it typically takes several minutes to several hours to decay to a negligible value. The leakage component of the stator insulation current is a continuous, irreversible current caused by the voltage applied to the surface of the test equipment with damaged or incomplete insulation. The leakage current varies depending on the temperature, humidity, contaminants, and voltage stress of the test environment, as well as the quality and condition of the insulation being tested.
The discharge current of the measured medium has only two components: capacitive current and depolarization current. During the discharge phase, there is no leakage current in the discharge current test because there is no external voltage source.
The DC insulation detection includes the following steps: 1, measure that polarization current of a detected stator win sample to obtain a polarization current change value. In the process of measuring the polarization current of the stator winding sample, connect the stator winding sample to a high-voltage DC power supply, and apply a DC voltage to the winding insulation within a certain period of time, with a voltage of 0.2 - 2K V per insulation thickness (per mm). The duration of the charging step is adjusted until the rate of change of the charging current is stable while the polarization current is continuously measured.
The ambient temperature, relative humidity, and winding capacitance shall be measured and recorded during the test. 2, perform depolarization current detection on that detected stator win sample to obtain a depolarization current change value. In that proces of measuring the depolarization current of the stator win sample, after the charging detection step is finished, the stator win of the generator is immediately short-circuited, the capacitive surge is discharged to be close to zero after several seconds of delay, and then the discharge (depolarization) current is measured. The ambient temperature, relative humidity, and winding capacitance shall be measured and recorded during the test. 3, The polarization and depolarization detection currents were normalized to the standard capacity temperature. The polarization and depolarization detection currents are normalized to the standard capacity temperature because the polarization and depolarization currents depend on the type, size, temperature, and quality of the insulation system, and in order to compare severkH504058 measurements of windings of different sizes and temperatures, the measured currents need to be normalized to remove the effects of winding capacitance and temperature. The change of normalized current will only be related to the insulation quality and insulation condition of the generator stator, so the trend analysis of these currents can be used as an indicator to identify the aging of insulation.
To normalize the charge-discharge current relative to the winding capacity, simply divide the measured current by the winding capacitance value. The performance of insulating materials is very dependent on temperature, so the influence of thermal effects must be eliminated from the test results. Since all measurements cannot be made at the same temperature, the measured current can be normalized to a common temperature, and all results are generally corrected to 40 °C.
The normalization of the measured current is performed using the following formula, since there is a relationship between the insulation resistance value of the stator winding at the measurement temperature and the resistance value at the reference temperature:
Re K+<Re
Where Rc is the insulation resistance corrected to 40 ° C, Rt is the insulation resistance (megohm) measured at temperature t, and Kt is the temperature coefficient of insulation resistance at temperature t. Therefore, the measured current value corrected to the uniform temperature and uniform capacity can be expressed as: it
Kix dg
C is the capacitance value of generator stator insulation winding, and Kt is the temperature coefficient of insulation resistance at temperature t. 4, drawing and analyzing the change condition of the measured current to judge the insulation level of the detected sample. The method for compare that insulation current tests comprise the following steps of: drawing a curve of the polarization current Chan along with the time and a curve of the depolarization current changing along with the time in the same coordinate chart, and observing the distance between the two curves so as to judge the insulation level of a test sample.
The principle is that the DC test polarization current of the test sample is calculated as Se
Where, f (t) is the dielectric response function, f (t) = At”, Cois the vacuum capacity, is the 904058 insulation conductivity, leat) represents the insulation leakage current, IleaxT) represents the insulation leakage current, and the depolarization current can be expressed as: idise(t) = VCO(6(t)+f(t)-f(t+te))
Since f (t) is a monotonically decreasing function of time, when tctends to infinity under ideal conditions, the second term of the above equation tends to zero, i.e., f(tHtc)=0
Therefore, it can be considered that Iaisc(t) = VCo(6 (t) + f (t)), and the distance between the two curves at the unified time point 1s [el
Do (0 — hc (0 = Vy + Healt) a
Therefore, the distance between the two curves is related to the magnitude of insulation leakage current, and the magnitude of insulation leakage current is positively related to the insulation level, so the distance between the two curves can reflect the insulation level of the stator. 5, Judge the relative distance between the polarization and depolarization current curves obtained from the insulation test of each phase winding. If there is a certain distance between the two curves, it can be qualitatively determined that the insulation level of the winding may decrease.
Preferably, as shown in Figure 4, when the vertical distance D between the polarization current curve and the depolarization current curve is less than 0.1 cm at the same time, It indicates that the insulation level of the stator is good and the resistance value Rd is greater than 1GQ; When the vertical distance D between the polarization current curve and the depolarization current curve is between 0.1 cm and 0.3 cm, it indicates that the insulation level of the stator decreases, and the insulation resistance value is 10 MQ < Rd < 1GQ; When the vertical distance between the polarization current curve and the depolarization current curve is greater than 0.3cm, it indicates that the insulation level of the stator is poor, and the insulation resistance value Rd is evaluated to be less than 10 MQ.
It should be noted that the decline of insulation level means that the main insulation of stator winding is inevitably affected by electrical, thermal, mechanical and other stresses during the operation of the motor, so the aging of insulation is actually the result of the combined effect of these stresses. In essence, aging is closely related to the generation and development of air gaps inside the main insulation and the deterioration of epoxy. Thermal stress causes embrittlement and degradation of epoxy resin and other materials, reduces the adhesion ability, and causes cracks or delamination in the insulation. Electrical stress causes air gap breakdown inside or on the surface of the insulation, and the heat, charged particles, ozone and other chemicals generated in the breakdown process further damage the insulation material. Mechanical strek$/504058 mainly includes electromagnetic mechanical force and thermal mechanical force of cold and hot cycles, which act on insulation for a long time and cause insulation wear, fatigue, delamination, cavitation or fracture.
When the insulation level of the stator winding to be verified decreases, that is, when D > 0.1, the stator insulation to be verified is subject to on-line partial discharge detection, and partial discharge will occur in the air gap of the insulator under high voltage. With the development of partial discharge, it will gradually corrode the insulation and lead to the aging of the insulator.
By measuring the partial discharge in the stator coil, the insulation state can be understood and the insulation performance of the motor stator can be evaluated. When the insulation is aging or the impregnation process is not good, the amount of partial discharge will increase significantly with the increase of the applied voltage. The partial discharge parameters include the maximum discharge capacity, the initial discharge capacity, the number of discharges, the pulse height, and the phase distribution diagram, etc. It should be pointed out that the partial discharge detection can be performed by using the prior art, and will not be described here.
Example 2
Referring to fig. 1 to fig. 5, a second embodiment of the present invention provides a method for detecting an insulation level of a stator of a gas turbine generator.
Specifically, the insulation of a generator stator is detected, and the parameters are as follows: the average running time of a 2500kW motor in the past is 7200h, and the number of starts and stops is 10.
First, check the appearance of stator insulation, and find that there is no obvious insulation damage such as insulation discoloration and discharge. DC insulation test is then performed on the stator insulation. The obtained insulation detection current curves of the three windings of the generator stator are shown in Figure 1 to Figure 3.
During the test, the current of the stator winding of the phase under test is measured separately, and the remaining non-measuring winding is not grounded and separated from the winding under test.
From Fig. 1 to Fig. 3, it can be seen that the polarization current and depolarization current measured by stator windings in different phases are different, especially for winding 2 and winding 3, when compared with the standard uncontaminated polarization and depolarization current change curve of stator winding, it can be found that there is no obvious deviation between the polarization and depolarization curve of stator winding with good insulation level.
For the stator winding currents in the example, there is a significant deviation between the polarized and depolarized currents for winding 2 and winding 3, with the relative deviation for winding 2 being greater. The reason is that the surface insulation pollution of winding 2 artkd/504058 winding 3 stator windings in their end winding areas causes the increase of leakage current during polarization, resulting in a large deviation between the measured polarization current and depolarization current, while the insulation pollution of winding 2 is more serious. From Figure 2, it can be seen that when t is 10 s, the distance between the two curves is smaller. At this time,
D = 0.413 is obtained through calculation by using the formula described in Embodiment 1. It can be seen from Fig. 3 that when t is about 20 s, the distance between the two curves is small, and D = 0.308 is obtained through calculation by using the formula. Therefore, it is preliminarily determined in this step that the insulation level of winding 2 and winding 3 in the stator insulation of the generator is suspected to decrease. And then the online partial discharge detection method is further used to accurately judge the winding suspected of insulation damage.
Finally, take the end of winding 2 as an example to detect the partial discharge, and the measured original partial discharge signal is shown in Figure 5. It can be seen from the signal that there is a phenomenon of partial discharge protrusion, indicating that there is indeed insulation damage at the end of the winding, which needs to be repaired or replaced.
It should be noted that the above embodiments are only used to illustrate the technical scheme of the present invention and are not limited. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical scheme of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical scheme, Which are intended to be included within the scope of the appended claims.
Claims (10)
1. A method for detecting the insulation level of a generator stator of a gas turbine generator set, comprising: Check the appearance of the stator insulation to determine whether there is any stain on the appearance; Carry out direct current polarization current detection on that stator insulation to be detected and jud whether the insulation level of the winding is reduced or not; When the insulation level of the stator winding to be detected is reduced, the insulation of the stator to be detected shall be subject to on-line partial discharge detection.
2. The method for detecting the insulation level of the stator of the gas turbine generator according to claim 1, wherein the direct current polarization current detection of the stator insulation to be detected comprises the following steps: carry out polarization current measurement on that detected stator win sample to obtain a polarization current change value; carry out depolarization current detection on a detected stator win sample to obtain a depolarization current change value; the polarization and depolarization detection currents were normalized to the standard volume temperature; drawing and analyzing the change of the measured current to judge the insulation level of the detected sample; according to the relative distance between the polarization current curve and the depolarization current curve obtained from the insulation test of each phase winding, it is determined whether there is a decline in the insulation level of the winding,
3.The method for detecting the insulation level of the stator of the gas turbine generator according to claim 2 is characterized in that when the polarization and depolarization detection current is normalized to the standard capacity temperature, the following formula is adopted: 110 Where, C is the capacitance value of generator stator insulation winding, and Kt is the temperature coefficient of insulation resistance at temperature t.
4. The method for detecting the insulation level of the stator of the gas turbine generator according to claim 3 is characterized in that the following formula is adopted when the stator winding sample is detected and the polarization current is measured:
ok LU504058 Sud Where f (t) is the dielectric response function, f (t) = At”, Cois the vacuum capacity, is the insulation conductivity, and Lea (t) represents the insulation leakage current.
5. The method for detecting the insulation level of the stator of the gas turbine generator according to claim 4 is characterized in that when the depolarization current detection is carried out on the detected stator winding sample, the following formula is adopted: idisc(t) = VCo(6(t)+F(t)-f(tHte)) Where, tcis the time for which the voltage is applied to the insulating layer, and since f (t) is a monotonically decreasing function of time, f (t + tc) = 0 when t (TS21) tends to infinity under ideal conditions, the above equation is: idise(t) = VCO(6(t)+f(t)) Where f (t) is the dielectric response function, f (t) = At”, and Cois the vacuum capacity.
6.The method for detecting the stator insulation level of a gas turbine generator according to claim 5, wherein the distance between the polarization and depolarization detection current curves at the same time point is calculated by the following formula: B=i, D bad = Vey + heed Where f (t) is the dielectric response function, f (t) = At", and Cois the vacuum capacity.
7. The method for detecting the insulation level of a generator stator of a gas turbine generator set according to any one of claims 2 to 6, which is characterized in that when the insulation of the stator to be detected is subjected to on-line partial discharge detection, the partial discharge parameters include maximum discharge quantity, initial discharge quantity, discharge times, pulse height, phase distribution map, and the like.
8. The method for detecting an insulation level of a stator of a gas turbine generator according to any one of claims 2 to 6, wherein: When the vertical distance between the polarization current curve and the depolarization current curve is less than 0.1 cm at the same time, it indicates that the stator insulation level is good.
9. The method for detecting the stator insulation level of a gas turbine generator according to any one of claims 2 to 6, wherein when the vertical distance between the polarization current curve and the depolarization current curve is between 0.1 cm and 0.3 cm at the same time, it indicates that the stator insulation level is reduced.
10. The method for detecting the stator insulation level of a gas turbine generator according to any one of claims 2 to 6, wherein when the vertical distance between the polarization current curve and the depolarization current curve is greater than 0.3cm at the same time, it indicates thk#/504058 the stator insulation level is poor.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210365014.8A CN114779021A (en) | 2022-04-07 | 2022-04-07 | Method for detecting insulation level of generator stator of gas turbine unit |
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| CN115902623B (en) * | 2023-01-09 | 2023-05-30 | 睿动(山西)科技有限公司 | Device for brushless motor test and control method thereof |
| CN116298734B (en) * | 2023-05-05 | 2023-10-27 | 南方电网调峰调频发电有限公司检修试验分公司 | Method, device, equipment and medium for testing insulation performance of engine stator |
| CN117554766B (en) * | 2024-01-09 | 2024-03-26 | 成都瑞讯物联科技有限公司 | Insulation on-line monitoring method and monitoring device |
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