CN116840637A - Insulation state testing method for motor component - Google Patents
Insulation state testing method for motor component Download PDFInfo
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- CN116840637A CN116840637A CN202310799335.3A CN202310799335A CN116840637A CN 116840637 A CN116840637 A CN 116840637A CN 202310799335 A CN202310799335 A CN 202310799335A CN 116840637 A CN116840637 A CN 116840637A
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Classifications
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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
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/025—Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2617—Measuring dielectric properties, e.g. constants
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2688—Measuring quality factor or dielectric loss, e.g. loss angle, or power factor
- G01R27/2694—Measuring dielectric loss, e.g. loss angle, loss factor or power factor
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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
- G01R31/003—Environmental or reliability tests
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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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Abstract
The embodiment of the disclosure provides a method for testing the insulation state of a motor component, which comprises the following steps: heating the motor component to a first preset temperature T1; immersing the motor part in water with the temperature being the third preset temperature T3 under the condition that the temperature of the motor part is more than or equal to the second preset temperature T2, wherein T1 is more than or equal to T2> T3; circularly executing the heating step and the soaking step for preset times C; and drying the motor part, testing the dielectric property of the motor part, and judging the insulation state of the motor part according to the test parameters of the dielectric property. Through the steps of heating and soaking the motor part, the extreme working condition that the motor is suddenly in rainy days after running at high temperature is simulated, and the high-temperature motor part is directly subjected to forced water cooling, so that the mechanical stress and the environmental stress of an insulation system of the motor part can be evaluated at the same time, and the accuracy of insulation reliability evaluation of the motor part is higher.
Description
Technical Field
The disclosure relates to the technical field of wind power generation, in particular to a method for testing an insulation state of a motor component.
Background
The permanent magnet direct-driven wind driven generator has large volume, heavy weight and extremely high lifting and dismounting cost, so that an insulation system of the permanent magnet direct-driven wind driven generator needs to have extremely high reliability and long service life, and the core for determining the service life of the permanent magnet direct-driven wind driven generator is the reliability of the insulation system.
The existing insulating state evaluation method generally adopts a high-temperature and low-temperature two-box method or a high-temperature method, air is placed after the high temperature is carried out, or liquid nitrogen is introduced for circulation after the high temperature is carried out, the heating and cooling speed is greatly affected by the weight (namely heat capacity) of a workpiece, an external cooling medium needs to have great heat capacity to enable the workpiece to be cooled down rapidly, the existing high-temperature and low-temperature test can set and evaluate the moisture resistance characteristic, the existing high-temperature and low-temperature test can be carried out after the high-temperature and low-temperature circulation test, the existing high-temperature and low-temperature test is placed in a humidity box, and the working condition is more consistent with the fact that equipment is in such a damp-heat environment without evaluating stricter working conditions, for example: after the generator stator operates, when the generator stator is in a heating state, heavy rain suddenly drops, a large amount of rainwater flows into the equipment, on one hand, a high-low temperature impact cooling process exists simultaneously, on the other hand, a water soaking process exists under cold and hot impact, and the two aspects simultaneously act on an insulation system, so that the conventional general evaluation thought is not suitable for evaluating the more extreme working condition, and the reliability of products cannot be guaranteed.
Disclosure of Invention
The present disclosure aims to at least solve the problem that the insulation state evaluation method in the prior art or related art cannot evaluate an extreme state of a generator stator in a rainy environment at a high temperature, and cannot guarantee reliability of a product.
In view of the above object, an embodiment of a first aspect of the present disclosure provides a method for testing an insulation state of a motor component, including: heating the motor component to a first preset temperature T1; immersing the motor part in water at a third preset temperature T3 when the temperature of the motor part is greater than or equal to a second preset temperature T2, wherein T1 is greater than or equal to T2 and is greater than or equal to T3; circularly executing the heating step and the soaking step for preset times C; and drying the motor component, testing the dielectric property of the motor component, and judging the insulation state of the motor component according to the test parameters of the dielectric property.
In some embodiments, the second preset temperature T2 and the third preset temperature T3 satisfy: T2-T3 is greater than or equal to 80 O C。
In some embodiments, during the heating step of the motor, the motor component is maintained at a temperature T1 for a first preset period of time T1, and 3 h.ltoreq.t1.ltoreq.5h.
In some embodiments, in the flooding step, the motor component is maintained in a flooded state for a second preset time period t2, the second preset time period t2 satisfying: t2 is more than or equal to 1h and less than or equal to 24h.
In some embodiments, after each of the heating operations is completed and before immersing the motor part in water, it is determined whether the temperature of the motor part is equal to or higher than a second preset temperature T2, and if the temperature of the motor part is lower than the second preset temperature T2, the motor part is heated again until the temperature of the motor part rises to the second preset temperature T2, and then the step of immersing the motor part in water is performed.
In some embodiments, the insulation state testing method further comprises the step of testing the dielectric properties of the motor component at a time node,
(e) After each execution of the heating step and before the soaking step;
(f) Each time the motor part is just immersed in water;
(g) When the motor member is immersed in water for a predetermined time;
(h) After the motor part is removed from the water tank and before a heating operation is performed.
In some embodiments, a temperature sensor is disposed in the motor component, for detecting the temperature of the motor component in real time, a lead of the temperature sensor is led out from the motor component, one end of the lead is exposed to the water surface and kept dry in a soaking operation, and the insulation state testing method further includes reading detection values of the temperature sensor at the time nodes (a), (b), (c), (d).
In some embodiments, the motor component is a part of a stator of a direct-drive wind generating set in a circumferential direction, and includes a stator core and a coil wound on the stator core.
In some embodiments, the motor component is 1/3-1/24 of the circumferential direction of the stator.
In some embodiments, in the step of heating the motor part, the motor part is placed in an oven for heating, after the heating operation is completed, the motor part is moved out of the oven and placed in a soaking tank, and after each movement of the motor part out of the oven and before the motor part is soaked, the dielectric properties of the coils of the motor part are tested, wherein in a plurality of cycles, the odd and even present coils are tested in turn.
In some embodiments, the parameter of dielectric properties includes at least one of insulation resistance, dielectric loss factor, and capacitance to ground parameter.
According to the insulation state testing method for the motor component, through the steps of heating and soaking the motor component, the temperature of water is lower than the temperature of the motor component before the motor component is soaked, the extreme working condition that the motor is suddenly in rainy days after running at high temperature is simulated, the high-temperature motor component is directly subjected to forced water cooling, the insulation system of the motor component is obviously expanded and contracted due to the large difference of the coefficients of thermal expansion caused by internal heat and external heat, so that the mechanical stress and the environmental stress of the insulation system of the motor component can be evaluated at the same time, the accuracy of insulation reliability evaluation of the motor component is higher, and the reliability of the motor component in a long-term use process can be improved. And the heating step and the soaking step are circularly executed for a plurality of times, so that the extreme working condition that the motor is suddenly in contact with rainy days after running at high temperature in the using process of the product can be simulated, and the accuracy of insulation reliability assessment of the motor parts can be further improved. The testing method is simple in operation steps, convenient to operate, suitable for evaluating the insulation performance of the large motor, and particularly has good revealing effect on the direct-drive wind generating set and the large motor with similar working conditions.
Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
Drawings
The above and other objects and features of the present application will become more apparent from the following description of embodiments of the present application taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a flow diagram of a method of testing the insulation status of a motor component according to one embodiment of the application;
fig. 2 is a schematic diagram showing a test procedure of cold and hot impact of a motor part in a method for testing an insulation state of a motor part according to an embodiment of the present application.
Detailed Description
The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, apparatus, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent after an understanding of the present disclosure. For example, the order of operations described herein is merely an example and is not limited to those set forth herein, but may be altered as will be apparent after an understanding of the disclosure, except for operations that must occur in a specific order. Furthermore, descriptions of features known in the art may be omitted for clarity and conciseness.
The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent after an understanding of the present disclosure.
As used herein, the term "and/or" includes any one of the listed items associated as well as any combination of any two or more.
Although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first member, first component, first region, first layer, or first portion referred to in the examples described herein may also be referred to as a second member, second component, second region, second layer, or second portion without departing from the teachings of the examples.
In the description, when an element such as a layer, region or substrate is referred to as being "on" another element, "connected to" or "coupled to" the other element, it can be directly "on" the other element, be directly "connected to" or be "coupled to" the other element, or one or more other elements intervening elements may be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" or "directly coupled to" another element, there may be no other element intervening elements present.
The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. Singular forms also are intended to include plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, amounts, operations, components, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, amounts, operations, components, elements, and/or combinations thereof. The term "plurality" represents two and any number of two or more.
The definition of the terms "upper", "lower", "top" and "bottom" in this disclosure are all based on the orientation of the product when in normal use, when placed upright.
Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless explicitly so defined herein, terms such as those defined in a general dictionary should be construed to have meanings consistent with their meanings in the context of the relevant art and the present application and should not be interpreted idealized or overly formal.
In addition, in the description of the examples, when it is considered that detailed descriptions of well-known related structures or functions will cause ambiguous explanations of the present application, such detailed descriptions will be omitted.
There are four factors affecting the reliability of the insulation system of the motor, commonly referred to as insulation integrated stress, i.e., TEAM four-major stress (T-thermal stress, E-electrical stress, a-ambient stress, M-thermo-mechanical stress), specifically explained by the fact that the motor is subjected to various stresses that occur periodically or persist during use. For each generator or electrical equipment, when designing an insulation system, stress investigation work is needed to be performed firstly for determining main stress factors affecting the reliability of the insulation system, and after the main stress factors are investigated, stress boundary parameters are needed to be extracted for designing an aging evaluation test scheme.
The inventor researches that for a direct-drive wind driven generator, the voltage level is generally not more than 1000V, the direct-drive wind driven generator belongs to low-voltage electric equipment, the insulation system is not obvious in the influence of electric stress, and the insulation system is generally thinner in order to evaluate the process fault tolerance. The general limiting use temperature of the direct-drive wind driven generator is 135 ℃, the highest temperature is lower, the insulation system is generally an F-level insulation system, namely the long-term heat-resistant temperature of the insulation system is 155 ℃, so that the influence of thermal stress is not obvious for the direct-drive wind driven generator, and the influence belongs to secondary influence. The direct-drive wind driven generator is generally in direct contact with the environment under the working condition that moisture/condensation/rain and the like are the most obvious environmental influence in the air, in addition, the volume and weight of the direct-drive wind driven generator are very large, so that the heat capacity of the direct-drive wind driven generator is also very large, after the direct-drive wind driven generator is operated for a period of time, the temperature of a stator of the direct-drive wind driven generator is continuously stabilized at a higher temperature and is generally not more than 135 ℃, in this case, if the rain working condition suddenly occurs, the stator is directly subjected to forced water cooling, an insulation system of the direct-drive wind driven generator is subjected to internal heat and external cooling, the insulation system is subjected to great difference of thermal expansion coefficients, obvious thermal expansion and contraction are caused, namely, the insulation system is generally made of nonmetallic substances, the insulation system of the direct-drive wind driven generator is generally subjected to cross-linking, solidification and molding after the insulation paint is soaked in a mode of a molding winding vacuum pressure dipping technology (VPI, vacuum Pressure Impregnating), and under the mechanical stress effect, whether the insulation state of a winding is damaged or not needs to be known through a test.
Under the working condition that the high temperature state is suddenly subjected to rainfall, mechanical stress can form micro-cracks, when moist air or moisture exists outside, whether the moisture invades into an insulation system or not, the micro-cracks can bombard chain segments of high polymer materials under the action of high heat, whether the micro-cracks continue to develop to fail or not, after the micro-cracks are generated, whether continuous cold and heat shrinkage can be aggravated or not, and whether the insulation system can withstand the working condition of the mechanical stress and environmental stress in a composite state or not.
The application discloses a very severe evaluation method for heating mechanical stress by environmental stress, which can be used for evaluating the insulation state of the motor part when an old insulation system is optimized or a new insulation system is introduced.
A method for testing an insulation state of a motor part according to an embodiment of the present application will be described with reference to fig. 1 and 2.
Fig. 1 shows a flow diagram of a method of testing the insulation state of a motor component according to an embodiment of the application.
As shown in fig. 1, the present application provides a method for testing an insulation state of a motor component, comprising: heating the motor component to a first preset temperature T1; immersing the motor part in water with the temperature being the third preset temperature T3 under the condition that the temperature of the motor part is more than or equal to the second preset temperature T2, wherein T1 is more than or equal to T2> T3; circularly executing the heating step and the soaking step for preset times C; and drying the motor part, testing the dielectric property of the motor part, and judging the insulation state of the motor part according to the test parameters of the dielectric property.
According to the insulation state testing method for the motor component, through the steps of heating and soaking the motor component, the temperature of water is lower than the temperature of the motor component before the motor component is soaked, the extreme working condition that the motor is suddenly in rainy days after running at high temperature is simulated, the high-temperature motor component is directly subjected to forced water cooling, the insulation system of the motor component is obviously expanded due to the large difference of the coefficients of thermal expansion caused by internal heat and external cooling, and obvious expansion and contraction of the insulation system of the motor component are caused, so that the mechanical stress and the environmental stress of the insulation system of the motor component can be evaluated at the same time, the accuracy of insulation reliability evaluation of the motor component is higher, and the reliability of the motor component in a long-term use process can be improved. And the heating step and the soaking step are circularly executed for a plurality of times, so that the extreme working condition that the motor is suddenly in contact with rainy days after running at high temperature in the using process of the product can be simulated, and the accuracy of insulation reliability assessment of the motor parts can be further improved. The testing method is simple in operation steps, convenient to operate, suitable for evaluating the insulation performance of the large motor, and particularly has good revealing effect on the direct-drive wind generating set and the large motor with similar working conditions.
Further, after the number of times of circularly executing the heating step and the soaking step reaches the preset number of times C, drying the motor component, and then performing a dielectric property test of the motor component, wherein the test can be used for testing 3 parameters of insulation resistance, dielectric loss and capacitance to ground, comparing the test data with the test data before the test, and judging the rationality of the change of the test data by a certain index.
It should be noted that, regarding the relationship among the first preset temperature T1, the second preset temperature T2, and the third preset temperature, T1 is greater than or equal to T2> T3, the motor component is heated to the first preset temperature T1, and before the motor component is immersed in water, the temperature may be slightly reduced, and the first preset temperature T1 may also be maintained, so T1 is greater than or equal to T2, and in order to achieve the effect of cold and hot impact, T2 must be greater than T3.
Further, for the values of the second preset temperature T2 and the third preset temperature T3, in some embodiments, the second preset temperature T2 and the third preset temperature T3 satisfy: T2-T3 is greater than or equal to 80 O C. In order to achieve a good thermal shock effect, the second preset temperature T2 needs to be far greater than the temperature of water, specifically, the difference between the second preset temperature T2 and the temperature of water may be equal to or greater than 80 ℃, and the soaking test needs to be performed under the condition that the temperature of the motor component is equal to or greater than the second preset temperature T2, that is, the temperature difference before and after soaking is equal to or greater than 80 ℃, so that the motor component has enough temperature difference before and after soaking, and a good cooling shock effect is achieved.
It will be appreciated that warm water is generally employed, typically at a temperature between 20 ℃ and 40 ℃. The temperature difference between T2 and T3 may be 80 ℃,90 ℃, 100 ℃, etc., where T2 may take 125 ℃, 130 ℃, 135 ℃, 140 ℃ etc., as an example.
Further, the value of the first preset temperature T1 is related to the heat resistance grade of the insulating material, and in some embodiments, if the highest heat resistance temperature of the heat resistance grade of the insulating material used for the motor component is T0, t1+.t0+30 ℃. The reason for this is that when the insulating material is applied to the temperature of 30 ℃ higher than the highest temperature of the corresponding heat-resistant grade, that is, when the value of T1 is greater than t0+30 ℃, the aging of the insulating material can be rapidly accelerated due to the fact that the heating temperature is too high and exceeds the temperature range that the insulating material can bear, the insulating material can be aged quickly in the testing process, the test cannot be performed, and the value of the first preset temperature T1 is unreasonable.
It is understood that the insulation grade refers to the heat resistance grade of the insulation material used for the windings of the motor (or transformer). The insulating materials commonly used in motors and transformers are rated A, E, B, F, H. Each insulation class of insulation material has a corresponding limit allowable operating temperature (the temperature of the hottest spot of the motor or transformer winding). The heat resistance rating of the insulating material is common knowledge in the art and will not be described in detail herein.
Further, the second preset temperature T2 is equal to the highest temperature at which the motor components operate. By the arrangement, the soaking condition is set under a condition that is more severe than the limit condition encountered by the motor component in the normal use process, that is, the motor component generally cannot exceed the second preset temperature T2 in the normal use process, even if rainfall is suddenly encountered, the condition of cold and hot impact cannot be higher than the condition defined by the embodiment, so that the insulation state testing method of the motor component defined by the embodiment strictly considers the limit condition of the motor component in practical application, tests under the limit condition or even exceeds the limit condition, and the accuracy of the insulation reliability evaluation of the motor component is higher, thereby improving the reliability of the motor component in the long-term use process.
Further, for the manner in which the motor components are dried, in some embodiments, the step of drying the motor components includes: heating the motor component to a fourth preset temperature T4, and keeping the motor component at the fourth preset temperature T4 for a third preset time period T3; the motor component is cooled until the temperature of the motor component reaches room temperature. After the motor part finishes the heating step and the soaking step which are circularly executed, the motor part is heated until the temperature of the motor part is increased to a fourth preset temperature T4, the temperature is kept basically unchanged, and the third preset time period T3 is continued, the inside of the motor part can be ensured to be completely dried by controlling two parameters of the fourth preset temperature T4 and the third preset time period T3, the motor part is dried to the room temperature after being dried, the dielectric property and the insulation resistance of the motor part are tested in the room temperature state, and then the insulation state of the motor part can be more accurately judged according to the test parameters of the dielectric property and the measured value of the insulation resistance. The third preset time period t3 ranges from 8 hours to 12 hours, and the inside of the motor component can be ensured to be dried.
Further, in some embodiments, the fourth preset temperature T4 may be equal to the first preset temperature T1, so that the temperature of the oven is not required to be adjusted repeatedly, and the motor component is directly placed in the oven to be dried, so that the operation steps are simplified, the oven is not required to wait for temperature adjustment, and the time is saved.
In some embodiments, after each heating operation is finished and before the motor part is immersed, it is determined whether the temperature of the motor part is equal to or higher than a second preset temperature T2, and if the temperature of the motor part is lower than the second preset temperature T2, the motor part is heated again until the temperature of the motor part rises to the second preset temperature T2, and then the step of immersing the motor part is performed. Therefore, the motor part can be heated in time under the condition that the temperature of the motor part is lower than the second preset temperature T2, the temperature of the motor part before soaking is ensured to be more than or equal to the second preset temperature T2, and the second preset temperature T2 and normal-temperature water are ensured to have enough temperature difference, so that cold and hot impact is ensured to be formed.
In some embodiments, the insulation state testing method further comprises the step of testing the dielectric properties of the motor component at the following time nodes,
(i) After each heating step is performed and before the soaking step is performed (the test herein may test for all 3 parameters of insulation resistance, dielectric loss, capacitance to ground);
(j) Each time the motor part is immersed in water (the test only needs to test the insulation resistance, and the measurement value of the dielectric loss and the capacitance to ground parameter in water has no reference value);
(k) The predetermined time is when the motor part is immersed in water (the test herein only requires the insulation resistance to be tested, it being understood that the predetermined time may be any one or more of 1h, 2h, 3h immersed in water, of course the time may be selected according to the actual situation; preferably the predetermined time is when the immersing step is about to end, i.e. when the immersing time is about to reach or has reached the second preset time period t 2);
(l) After the motor part is removed from the water bath and before a heating operation is performed (the test here only requires testing of the insulation resistance).
In these embodiments, by testing the dielectric properties of the motor component at a plurality of time nodes during the cyclic execution of the heating step and the soaking step, it is possible to find out in time in the event of problems in the insulation state, during which problematic data and corresponding coils are timely focused; the test data of the dielectric properties of the motor parts in the process of multiple groups of cycles can be reserved, so that the time when the insulation state is problematic can be analyzed by analyzing the test data of the dielectric properties of the motor parts in the process of cycles after the test is finished, for example, the problem is started to occur in the test data of the dielectric properties of one group or two groups of coils in the fourth cycle period, and similar problems can be found, so that the improvement and optimization of an insulation system are facilitated. It will be appreciated that this is a process assurance test, also known as a split-cycle diagnostic test, and that the testing of the dielectric properties of the motor components during the multiple sets of cycles is generally not used as a final decision, is used to see the trend of insulation changes, and provides additional support for the final decision test, can document the subsequent evaluation test, and can also alert the testers and experimenters as to which coils are focused.
In some embodiments, a temperature sensor is disposed in the motor component, for detecting the temperature of the motor component in real time, a lead of the temperature sensor is led out from the motor component, and during the soaking operation, one end of the lead is exposed to the water surface and kept dry, and the insulation state testing method further includes reading the detection values of the temperature sensor at the time nodes (a), (b), (c), (d). The temperature sensor is embedded in the motor component, so that the temperature in the motor component can be measured more accurately; further, the detection values of the temperature sensors are read at the time nodes (a), (b), (c) and (d), so that the temperature can be detected on one hand, and whether the temperature sensors are damaged or not can be timely monitored on the other hand.
In some embodiments, the motor component is a stator, the temperature sensor is pre-buried in a winding of the stator, and a lead is arranged to be led out of the stator for acquiring the temperature measured by the temperature sensor through the lead.
In some embodiments, the temperature sensor may be a Pt100 resistor or a fiber optic sensor. The Pt100 resistor or the optical fiber sensor has the advantages of high temperature resistance and accurate measurement. Specifically, under the condition that the temperature sensor selects the Pt100 resistor, the specific step of acquiring the real-time temperature of the motor component comprises the steps of leading out a test wire of the Pt100 resistor, testing the resistance value of the Pt100 resistor, and when the temperature changes, the resistance value of the Pt100 resistor correspondingly changes, so that the temperature in the motor component can be acquired through testing the resistance value of the Pt100 resistor.
In some preferred embodiments, the motor component is a part of the stator of the direct drive wind turbine, including a stator core and a coil wound around the stator core. The method comprises the steps of taking silicon steel sheets in the production of a real stator, laminating, wherein the lamination rate and the lamination height are completely consistent with those of the real product, inserting coils in the production, insulating structures and process operations of the coils are completely consistent, motor parts have axial lengths consistent with those of the stator, the authenticity of the motor parts is high, and the conclusion obtained after testing is more accurate.
Further, in some embodiments, the height and arrangement of the ventilation channels in the stator core model are consistent with those of an actual stator, and all main structures in the structural model are real products.
In some embodiments, the motor component is 1/3-1/24 of the circumferential direction of the stator. The test device is enough to test and use, and waste caused by adopting more stator structures is avoided.
It will be appreciated that the stator of the direct drive wind power generator is large in size, and although it is a 1/24 stator, the weight of the direct drive wind power generator can reach more than 1.5 tons, and the heat capacity is large enough.
In a specific embodiment, in the soaking step, a part of the stator for testing is placed in a soaking groove filled with water in advance, the lead ends of the coils face upwards, the liquid level submerges the notch of the stator, the liquid level is 20mm higher than the notch of the stator, the lead faces upwards, various tests in water are avoided, the notch is generally an insulation system weak position, because the position has obvious structural change, the iron core and the ventilation channel in the stator are periodically changed, the structural form of the notch suddenly changes, the insulation structure in the groove in the stator is continuous, the extending length of the groove insulation paper after the notch is formed is 15mm, and the submerged notch is larger than 20mm so as to completely immerse the weak position of the notch position and ensure that the lead is in a dry state at the same time.
In some embodiments, in the step of heating the motor component, the motor component is placed in an oven for heating, so that the temperature of the whole motor component is conveniently raised, the temperature raising is rapid and reliable, and the temperature uniformity of each position of the motor component can be ensured as much as possible; after the heating operation is completed, the motor part is moved out of the oven and put into a soaking tank; the dielectric properties of the coils of the motor part are tested after each removal of the motor part from the oven and before the immersion of the motor part, wherein in a plurality of cycles, the odd coils and the even current coils are tested in turn, in particular, the plurality of coils of the motor part can be numbered, the dielectric properties of the coils numbered odd can be tested in cycles of the odd cycles (such as the 1 st cycle, the 3 rd cycle, the 5 th cycle, etc.), and the dielectric properties of the coils numbered even can be tested in cycles of the even cycles (such as the 2 nd cycle, the 4 th cycle, the 6 th cycle, etc.), so that only half of the coils need to be tested in each cycle, the test time is saved, and because all the coils can be tested alternately in the odd cycles and the even cycles, the accuracy of the data is ensured.
Of course, similarly, the dielectric properties of the even numbered coils may also be tested in cycles of odd numbered cycles (e.g., cycle 1, cycle 3, cycle 5, etc.), and the dielectric properties of the odd numbered coils may be tested in cycles of even numbered cycles (e.g., cycle 2, cycle 4, cycle 6, etc.), where the operation of coil numbering is merely to identify the individual coils and is not described in detail herein.
In some embodiments, the parameter of dielectric properties includes at least one of insulation resistance, dielectric loss factor, and capacitance to ground parameter. The insulation state of the motor component can be determined by the ratio of the capacitance increase to ground, the insulation resistance, and the contrast value and absolute value of the dielectric loss factor.
In some embodiments, during the heating step of the motor, the motor component is maintained at a temperature T1 for a first preset period of time T1, and 3 h.ltoreq.t1.ltoreq.5h. The arrangement ensures that the heating time of the motor part is enough, the internal and external temperatures of the motor part are consistent, and the temperature uniformity of the motor part is ensured.
In some embodiments, in the flooding step, the motor component is maintained in the flooded state for a second preset time period t2, the second preset time period t2 satisfying: t2 is more than or equal to 1h and less than or equal to 24h. On one hand, the water immersion time is enough, so that the inside and outside of the motor part can be ensured to be cooled, and the temperature is consistent; on the other hand, in practical application, because the motor all has the outlet, even in heavy rain weather is full by the rainwater, also can soak water for a short period of time, the outlet can be continuously outwards drained, and the soaking time generally can not exceed 0.5h, and the soaking time length is set to be more than one hour for this soaking operating mode also can simulate the motor and meet the conventional soaking of heavy rain weather in the in-service use.
In some embodiments, the preset number of times C is approximately equal to the theoretical limit number of high and low temperature impacts of the motor component over the lifetime. The preset times C are calculated according to the probability and the times of possible water soaking working conditions when the wind farm is operated, the stator temperature of the wind driven generator is very high only in heavy wind and heavy stormy weather, and a large amount of water enters the motor to be discharged out of the motor, so that the preset times C are 10 times, preferably 8-13 times, in the life time of the direct-driven wind driven generator.
Fig. 2 is a schematic diagram showing a test procedure of cold and hot impact of a motor part in a method for testing an insulation state of a motor part according to an embodiment of the present application.
As shown in fig. 2, the single cold and hot impact test procedure is described as follows: a) At the beginning of each cold and hot impact cycle, the motor component temperature is substantially room temperature; b) The motor part is put into the oven, and a test wire of Pt100 resistance is led out. Continuously heating the oven at the fastest speed, and starting to keep the temperature after the temperature of the motor part reaches a first preset temperature T1, wherein the temperature T1 is 145-155 ℃ optionally; c) After the heat preservation is carried out for a first preset time period t1, the motor component is moved out of the oven (or in the oven) to test the insulation resistance, the dielectric loss factor and the capacitance to ground parameter, and the Pt100 resistance value is tested after the insulation resistance, the dielectric loss factor and the capacitance to ground parameter are finished, wherein the test of the Pt100 resistance value is to know the temperature of the motor component on the one hand, and the function of determining the Pt100 resistance in the current state is good and is not damaged on the other hand. For the condition of moving out the oven for testing, because the temperature of the motor component of the moving out oven is relatively faster, the insulation resistance, the dielectric loss factor, the capacitance to ground parameter and the like of the motor component are prevented from being excessively long, and the temperature of the motor component is greatly reduced due to long-time testing, so that only odd coils can be tested in odd cycles of a cycle period, and only even coils can be tested in even cycles; d) After the above-mentioned insulation resistance, dielectric loss factor, and capacitance to ground parameter are tested, put into the water-immersed tank that holds water in advance under the condition that the temperature of the motor component is greater than or equal to the second preset temperature T2, for example, when the motor component is the running condition of the motor in the direct-drive wind generating set, T2 can take the value near the highest temperature that the motor component operates, alternatively, under the condition that the highest temperature that the motor component operates is 135 ℃, T2 can take 130 ℃ to 140 ℃, the lead end of the coil faces upwards, the height of the water-immersed notch is greater than 20mm, and meanwhile, the lead is ensured to be in a dry state; e) After the motor part is filled with water, the Pt100 resistance and the insulation resistance of the motor part are tested immediately; f) After the motor part is immersed for a second preset time period t2, testing the Pt100 resistance and the insulation resistance of the motor part; g) Lifting the motor part out of the water immersion tank, and testing the insulation resistance of the motor part; h) After the test is completed, the motor part is hung into the oven, and the next cold and hot impact cycle is started until the cycle reaches the preset times C.
It is worth to be explained that the insulation state testing method of the motor component provided by the embodiment of the application can be particularly applied to a direct-drive wind driven generator, and the direct-drive wind driven generator has high value, high maintenance cost and complex environmental stress. Further, in order to ensure the reliability of the direct-drive wind driven generator, the stator motor component is adopted to perform a cold and hot impact test when the insulation structure is changed or optimized, the cold and hot impact test is to perform cyclic heating and water diffusion on the stator motor component, and perform evaluation on the insulation sealing performance and the cold and hot impact resistance of the generator stator, so as to verify the adaptability of the insulation system performance after the existing insulation design or major design change to specific working conditions, in particular to cold and hot impact conditions.
Although embodiments of the present application have been described in detail hereinabove, various modifications and variations may be made to the embodiments of the application by those skilled in the art without departing from the spirit and scope of the application. It will be appreciated that such modifications and variations will be apparent to those skilled in the art that they will fall within the spirit and scope of the embodiments of the application as defined in the appended claims.
Claims (12)
1. A method of testing an insulation state of a motor component, the method comprising:
heating the motor component to a first preset temperature T1;
immersing the motor part in water at a third preset temperature T3 when the temperature of the motor part is greater than or equal to a second preset temperature T2, wherein,
T1≥T2>T3；
circularly executing the heating step and the soaking step for preset times C;
and drying the motor component, testing the dielectric property of the motor component, and judging the insulation state of the motor component according to the test parameters of the dielectric property.
2. The method for testing the insulation state of a motor component according to claim 1, wherein,
the second preset temperature T2 and the third preset temperature T3 satisfy: T2-T3 is greater than or equal to 80 O C。
3. The insulation state testing method of a motor component according to claim 1, wherein in the heating step of the motor, the motor component is maintained at a temperature T1 for a first preset period of time T1, and 3 h+.t1+.5h.
4. The method for testing the insulation state of a motor component according to claim 1, wherein,
in the immersing step, the motor component is kept in an immersed state for a second preset time period t2, and the second preset time period t2 satisfies: t2 is more than or equal to 1h and less than or equal to 24h.
5. The insulation state testing method of a motor part according to claim 1, wherein after each time the heating operation is ended and before immersing the motor part in water, it is judged whether the temperature of the motor part is equal to or higher than a second preset temperature T2, and if the temperature of the motor part is lower than the second preset temperature T2, the motor part is heated again until the temperature of the motor part rises to the second preset temperature T2, and then the step of immersing the motor part in water is performed.
6. The method for testing the insulation state of a motor component according to claim 1, wherein,
the insulation state testing method further includes the step of testing the dielectric properties of the motor component at the following time nodes,
(a) After each execution of the heating step and before the soaking step;
(b) Each time the motor part is just immersed in water;
(c) When the motor member is immersed in water for a predetermined time;
(d) After removal of the motor part from the water bath and before the next heating operation.
7. The method for testing the insulation state of a motor component according to claim 6, wherein,
the insulation state testing method comprises the steps of providing a motor part, wherein a temperature sensor is arranged in the motor part and used for detecting the temperature of the motor part in real time, a lead wire of the temperature sensor is led out from the motor part, one end of the lead wire is exposed to the water surface and kept dry in the soaking operation, and the insulation state testing method further comprises the step of reading detection values of the temperature sensor at the time nodes (a), (b), (c) and (d).
8. The method for testing the insulation state of a motor component according to any one of claims 1 to 7, wherein,
the motor component is a part of the stator of the direct-drive wind generating set in the circumferential direction and comprises a stator core and a coil wound on the stator core.
9. The method for testing the insulation state of a motor component according to claim 8, wherein,
the motor part is 1/3-1/24 of the circumference direction of the stator.
10. The method for testing the insulation state of a motor component according to any one of claims 1 to 7, wherein,
the second preset temperature T2 is equal to the highest temperature at which the motor element operates.
11. The method for testing the insulation state of a motor component according to claim 10, wherein,
in the step of heating the motor part, placing the motor part into an oven for heating, and after the heating operation is finished, moving the motor part out of the oven and placing the motor part into a soaking tank;
the dielectric properties of the coils of the motor parts were tested after each removal of the motor parts from the oven and before immersing the motor parts in water, wherein the odd and even present coils were tested in turn over a number of cycles.
12. The insulation state testing method of a motor component according to any one of claims 1 to 7, wherein the parameters of dielectric properties include at least one of insulation resistance, dielectric loss factor, and capacitance to ground parameter.
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| CN202310799335.3A CN116840637B (en) | 2023-06-30 | Insulation state testing method for motor component |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20090070319A (en) * | 2007-12-27 | 2009-07-01 | 주식회사 포스코 | Methode for measuring coating strength of tention insulting coationg layer of oriented electric steel |
| CN103823166A (en) * | 2014-02-28 | 2014-05-28 | 武汉大学 | Fatigue test device and method for solid insulation degradation process |
| CN104734391A (en) * | 2015-04-17 | 2015-06-24 | 苏州贝得科技有限公司 | Closed type ammonia-resistant motor and preparation method thereof |
| CN104868666A (en) * | 2015-04-30 | 2015-08-26 | 株洲南车机电科技有限公司 | Primary insulation processing method for linear motor for rail traffic vehicle |
| CN112526296A (en) * | 2019-09-19 | 2021-03-19 | 新疆金风科技股份有限公司 | Insulation testing device and method |
| CN113030672A (en) * | 2019-12-24 | 2021-06-25 | 新疆金风科技股份有限公司 | Testing device, testing method and insulating property testing method |
| CN113358948A (en) * | 2020-03-05 | 2021-09-07 | 新疆金风科技股份有限公司 | Environmental suitability test method and test equipment |
| WO2023072174A1 (en) * | 2021-11-01 | 2023-05-04 | 南方电网调峰调频发电有限公司检修试验分公司 | Method for determining insulation thermomechanical deterioration of vpi wire rod of pumped storage power generation motor |
| CN116087767A (en) * | 2022-12-21 | 2023-05-09 | 浙江凌昇动力科技有限公司 | Method, device, equipment and medium for reliability test and life prediction of generator |
| DE102021214577A1 (en) * | 2021-12-17 | 2023-06-22 | Zf Friedrichshafen Ag | Method of heating and cooling a component of an engine |
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20090070319A (en) * | 2007-12-27 | 2009-07-01 | 주식회사 포스코 | Methode for measuring coating strength of tention insulting coationg layer of oriented electric steel |
| CN103823166A (en) * | 2014-02-28 | 2014-05-28 | 武汉大学 | Fatigue test device and method for solid insulation degradation process |
| CN104734391A (en) * | 2015-04-17 | 2015-06-24 | 苏州贝得科技有限公司 | Closed type ammonia-resistant motor and preparation method thereof |
| CN104868666A (en) * | 2015-04-30 | 2015-08-26 | 株洲南车机电科技有限公司 | Primary insulation processing method for linear motor for rail traffic vehicle |
| CN112526296A (en) * | 2019-09-19 | 2021-03-19 | 新疆金风科技股份有限公司 | Insulation testing device and method |
| CN113030672A (en) * | 2019-12-24 | 2021-06-25 | 新疆金风科技股份有限公司 | Testing device, testing method and insulating property testing method |
| CN113358948A (en) * | 2020-03-05 | 2021-09-07 | 新疆金风科技股份有限公司 | Environmental suitability test method and test equipment |
| WO2023072174A1 (en) * | 2021-11-01 | 2023-05-04 | 南方电网调峰调频发电有限公司检修试验分公司 | Method for determining insulation thermomechanical deterioration of vpi wire rod of pumped storage power generation motor |
| DE102021214577A1 (en) * | 2021-12-17 | 2023-06-22 | Zf Friedrichshafen Ag | Method of heating and cooling a component of an engine |
| CN116087767A (en) * | 2022-12-21 | 2023-05-09 | 浙江凌昇动力科技有限公司 | Method, device, equipment and medium for reliability test and life prediction of generator |
Non-Patent Citations (2)
| Title |
|---|
| 张晓强 等: "环氧改性不饱和聚酯亚胺浸渍树脂在直驱风力发电机定子上的应用研究", 绝缘材料, vol. 55, no. 1, pages 0 - 3 * |
| 陈洪武;车三宏;: "基于防水性能的永磁直驱风力发电机绝缘结构", 电机与控制应用, vol. 39, no. 06, pages 37 - 42 * |
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