A flexible main insulation structure for high voltage motor stator coils

Abstract

The application discloses a high-voltage motor stator coil flexible main insulation structure and relates to the technical field of high-voltage motor coils.The main insulation layer is divided into a groove portion area, a slot outlet area, an end portion area and a lead area which are sequentially connected, the main insulation thickness d1 of the groove portion area is thinned, the main insulation thickness d2 of the slot outlet area is gradually increased and then gradually decreased from the end of the groove portion area, d2 is not less than d1, the main insulation thickness d3 of the end portion area is linearly thinned from the end of the slot outlet area, the main insulation thickness of the lead area is d4, and d4 is not greater than d3.The main insulation of the groove portion area and the end portion area of the stator coil is thinned, the slot fullness of the motor and the bevel gap of the coil end portion are increased, the volume of the motor is reduced, and the manufacturing cost of the motor is reduced.The main insulation of the slot outlet area of the stator coil is thickened, the overall electrical strength and the operation life of the stator coil insulation are effectively improved, and the stable reliability of the motor installation and long-term operation is ensured.

Description

Technical Field

[0001] This invention relates to the field of high-voltage motor coil technology, and in particular to a flexible main insulation structure for a high-voltage motor stator coil. Background Technology

[0002] The main insulation structure of the stator coil is a key core technology of high-voltage motors. During the manufacturing and operation of the stator coil insulation, it is subjected to stresses from electricity, heat, machinery and environment. The service life of the motor mainly depends on the service life of the stator coil insulation. The insulation performance of the stator coil plays a vital role in the safe and reliable operation of the motor.

[0003] Currently, the design schemes for the main insulation structure of high-voltage motor stator coils both domestically and internationally involve the same insulation thickness in the slot region, slot outlet region, and end region, or the same insulation thickness in the slot region and slot outlet region, with a slightly thinner insulation thickness in the end region. There is no systematic consideration of the different stress factors experienced by the insulation in different regions for refined design. The insulation region of a high-voltage motor stator coil can be mainly divided into four areas: the slot region, the slot outlet region, the end region, and the lead region. The weakest area is the slot outlet region, where electrical stress is concentrated due to electric field distortion. The capacitive current of the end insulation layer and the resistive current of the anti-corona layer converge in the slot outlet region, resulting in high heat loss. The slot outlet region is also the most vulnerable to damage during assembly, winding, operation, and maintenance. In comparison, the electrical stress experienced by the coil slot region is the same as that of the slot outlet region, but the thermal and mechanical stresses are lower. The electrical, thermal, and mechanical stresses experienced by the coil end region are all lower than those of the slot region. The lead region experiences virtually no electrical stress, only relatively small thermal and mechanical stresses.

[0004] Traditional high-voltage motors have a large insulation thickness margin in the slot and end portions of the stator coils, but a small margin in the slot exit area. More than 60% of insulation breakdowns occur in the slot exit area. Therefore, it is necessary to develop a flexible main insulation structure for the stator coils to ensure the electromechanical performance of the main insulation. Summary of the Invention

[0005] The purpose of this invention is to propose a flexible main insulation structure for the stator coil of a high-voltage motor. Based on the stress factors such as electrical stress, thermal stress, and mechanical stress actually borne by different parts of the stator coil of the high-voltage motor, and in combination with the rated operating voltage of the unit, a refined design with different main insulation thicknesses is carried out for the slot area, slot outlet area, end area, and lead wire area of ​​the stator coil, under the premise of ensuring the electromechanical performance of the main insulation of the stator coil, so as to solve the above-mentioned problems.

[0006] The technical solution adopted in this invention is as follows:

[0007] This invention relates to a flexible main insulation structure for a high-voltage motor stator coil, comprising stator conductors and an external main insulation layer. The main insulation layer is divided into a slot region, a slot outlet region, an end region, and a lead wire region connected in sequence.

[0008] The main insulation thickness of the groove region is d1. By reducing the main insulation thickness d1 of the groove region, the main insulation thickness of the groove region becomes equal.

[0009] The main insulation thickness of the slot outlet area is d2. The main insulation thickness d2 of the slot outlet area gradually increases and then gradually decreases from the end of the slot area, and d2 is not less than d1.

[0010] The main insulation thickness of the end region is d3. The main insulation thickness d3 of the end region is reduced, and the main insulation thickness d3 of the end region is linearly reduced from the end of the slot opening region. The main insulation thickness d3 at the front end of the end region is greater than the main insulation thickness d1 of the slot region, and the main insulation thickness d3 at the end of the end region is less than the main insulation thickness d1 of the slot region.

[0011] The main insulation thickness of the lead area is d4, which is not greater than the main insulation thickness d3 of the end area, and the main insulation thickness of the lead area is equal.

[0012] Furthermore, the main insulation wrapping length of the slot region is L1, which is Lx longer than one end of the stator core L0. The distance between the starting position of the main insulation wrapping in the slot region and the end of the stator core is Lx, which increases with the increase of the rated voltage of the high-voltage motor.

[0013] Furthermore, the value of Lx varies depending on the rated voltage of the motor, and the specific design formula is as follows:

[0014] L X =1.6×U N +206≤U N ≤30

[0015] Where Lx is the length distance from one end of the stator core to one end of the main insulation in the slot region, and U N This refers to the rated line voltage value of the high-voltage motor.

[0016] Furthermore, the design formula for the main insulation thickness d1 of the groove region is as follows:

[0017]

[0018] Wherein, K is selected based on the motor's operating characteristics and insulation life requirements, with a value range of 2.6 to 3.3, and U... N This refers to the rated line voltage value of the high-voltage motor.

[0019] Furthermore, the main insulation wrapping length in the slot outlet area is L2, which increases with the increase of the rated voltage of the high-voltage motor. The specific design formula for the wrapping length range L2 is as follows:

[0020] L2 = 3.3 × U N +1006≤U N ≤30

[0021] Among them, U N This refers to the rated line voltage value of the high-voltage motor.

[0022] Furthermore, the main insulation wrapping thickness d2 in the slot outlet area, within the insulation wrapping length L2 of the slot outlet area, gradually increases and then gradually decreases from the end of the slot area. The main insulation wrapping thickness d2 in the slot outlet area is determined according to the rated voltage of the high-voltage motor. The specific design formula for the main insulation thickness d2 in the slot outlet area is as follows:

[0023]

[0024] Where d1 is the main insulation thickness of the slot region of the stator coil, U N This refers to the rated line voltage value of the high-voltage motor.

[0025] Furthermore, the end of the end region is the starting end of the main insulation wrapping of the lead region. The main insulation of the lead region needs to withstand mechanical stress and thermal stress. The thickness d4 of the main insulation of the lead region is not less than 2mm, and the thickness d4 is not greater than the thickness d3 of the main insulation of the end region.

[0026] Furthermore, the main insulation wrapping thickness d3 in the end region decreases linearly from the end of the main insulation in the slot opening region, and varies depending on the rated voltage of the motor. The specific design formula for the main insulation thickness d3 in the end region is as follows:

[0027]

[0028] Where d1 is the main insulation thickness of the slot region of the stator coil, U N L1 represents the rated line voltage of the high-voltage motor, and L3 represents the length of the main insulation wrapping in the end area.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] 1. This invention is a flexible main insulation structure for the stator coil of a high-voltage motor. Based on the stress factors such as electrical stress, thermal stress and mechanical stress actually borne by different parts of the stator coil of the high-voltage motor, and combined with the rated operating voltage of the unit, the main insulation thickness of the stator coil in the slot area and end area with large margin is reduced while ensuring the electromechanical performance of the main insulation of the stator coil. This reduces the cost of coil materials, increases the slot fill factor of the motor, reduces the size of the motor, and reduces the overall weight of the motor.

[0031] 2. This invention is a flexible main insulation structure for a high-voltage motor stator coil. It features a refined design for the main insulation wrapping length in the stator coil slot area, coil exit area, and end area, thereby improving the dimensional accuracy of the stator coil main insulation wrapping and effectively enhancing the digital production efficiency of stator coil insulation.

[0032] 3. This invention is a flexible main insulation structure for the stator coil of a high-voltage motor. It thickens the main insulation in areas with small thickness margins in the slot exit region of the stator coil, thereby increasing the mechanical and electrical strength of the main insulation in the slot exit region. This significantly reduces the risk of mechanical stress damage to the insulation in the slot exit region caused by parallel straightening during stator coil handling, transportation, and winding. It effectively improves the overall electrical strength and service life of the stator coil insulation, ensuring the stability and reliability of the unit's long-term operation.

[0033] 4. This invention is a flexible main insulation structure for the stator coil of a high-voltage motor. The thickness of the insulation at the end of the stator coil is matched according to the rated voltage of the unit to avoid excessive thinning of the insulation at the end of the coil, which would cause an increase in the surface potential of the insulation and result in corona discharge of the unit. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein:

[0035] Figure 1 This is a schematic diagram of the external main insulation structure of the stator coil;

[0036] Figure 2 This is a cross-sectional view of the flexible main insulation structure of the stator coil.

[0037] Explanation of reference numerals in the attached drawings: 1-slot area, 2-outlet area, 3-end area, 4-lead area, 5-stator conductor. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] It should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0041] Example 1

[0042] like Figure 1-2 As shown, the present invention is a flexible main insulation structure for a high-voltage motor stator coil, including a stator conductor 5 and a main insulation layer outside it. The main insulation layer is divided into a slot region 1, a slot outlet region 2, an end region 3 and a lead wire region 4 connected in sequence.

[0043] The main insulation layer of the stator conductor 5 is wrapped with mica tape in each region. Based on the stress factors, such as electrical, thermal, and mechanical stresses, actually borne by different parts of the high-voltage motor stator coil, and combined with the rated operating voltage of the unit, the main insulation thickness is reduced in areas with a large margin in the slot region 1 and end region 3, while ensuring the electromechanical performance of the stator coil main insulation. This reduces coil material costs, increases the motor slot fill factor, and reduces motor size. The main insulation thickness is thickened in areas with a small margin in the slot exit region 2, increasing the mechanical and electrical strength of the main insulation in the stator winding slot exit region 2 and improving the stability and reliability of the motor during installation and operation. The specific design of the main insulation thickness and length for each region is as follows:

[0044] The main insulation thickness of the groove region 1 is d1. By reducing the main insulation thickness d1 of the groove region 1, the main insulation thickness of the groove region 1 becomes equal.

[0045] Specifically, the design formula for the main insulation thickness d1 of the groove region 1 is as follows:

[0046]

[0047] Wherein, K is selected based on the motor's operating characteristics and insulation life requirements, with a value range of 2.6 to 3.3, and U...N This refers to the rated line voltage value of the high-voltage motor.

[0048] Preferably, the main insulation wrapping length of the slot region 1 is L1. In order to ensure the electrical strength of the main insulation of the stator coil slot region 1, L1 is longer than one end of the stator core L0 by Lx. The distance between the starting position of the main insulation wrapping of the slot outlet region 2 and the end of the stator core is Lx. Lx increases with the increase of the rated voltage of the high-voltage motor.

[0049] The value of Lx varies depending on the rated voltage of the motor, and the specific design formula is as follows:

[0050] L X =1.6×U N +206≤U N ≤30

[0051] Where Lx is the length distance from one end of the stator core to the main insulation end of slot region 1, and U N This refers to the rated line voltage value of the high-voltage motor.

[0052] In this embodiment, Lx is 40mm, that is, one end of the stator core is 40mm away from the end of the main insulation of the slot region 1, both ends of the main insulation of the slot region 1 are 40mm away from the end of the stator core, and the length L1 of the main insulation of the slot region 1 is greater than the length of the stator core by 80mm.

[0053] The main insulation thickness of the slot opening area 2 is d2. The main insulation thickness d2 of the slot opening area 2 gradually increases and then gradually decreases from the end of the slot area 1, and d2 is not less than d1.

[0054] Specifically, the main insulation wrapping thickness d2 of the slot outlet region 2 gradually increases and then gradually decreases starting from the end of the slot region 1. Within the insulation wrapping length L2 of the slot outlet region 2, the main insulation thickness d2 gradually increases and then gradually decreases. The main insulation wrapping thickness d2 of the slot outlet region 2 is determined according to the rated voltage of the high-voltage motor. The specific design formula for the main insulation thickness d2 of the slot outlet region 2 is as follows:

[0055]

[0056] Where d1 is the main insulation thickness of slot region 1 of the stator coil, U N This refers to the rated line voltage value of the high-voltage motor.

[0057] Preferably, the main insulation wrapping length of the slot outlet area 2 is L2, which increases with the increase of the rated voltage of the high-voltage motor. The specific design formula for the wrapping length range L2 is as follows:

[0058] L2 = 3.3 × UN +1006≤U N ≤30

[0059] Among them, U N This refers to the rated line voltage value of the high-voltage motor.

[0060] To avoid excessively long wrapping length of the thickened main insulation in slot exit area 2, which could affect the chamfer gap size at the stator coil end, the wrapping length of the main insulation in slot exit area 2 is precisely designed according to the different rated voltage values ​​of the motor. Meanwhile, to prevent the starting position of the insulation wrapping in slot exit area 2 from being too close to the end of the stator core, thus avoiding dimensional interference when the stator coil is embedded in the stator core slot, the distance between the starting position of the main insulation wrapping in slot exit area 2 and the end of the stator core is 40mm.

[0061] The main insulation thickness of the end region 3 is d3. The main insulation thickness d3 of the end region 3 is reduced, and the main insulation thickness d3 of the end region 3 is linearly reduced from the end of the slot outlet region 2. The main insulation thickness d3 at the front end of the end region 3 is greater than the main insulation thickness d1 of the slot region 1, and the main insulation thickness d3 at the end of the end region 3 is less than the main insulation thickness d1 of the slot region 1.

[0062] Preferably, the main insulation wrapping thickness d3 of the end region 3 decreases linearly from the end of the main insulation in the slot region 2, and is determined according to the different rated voltages of the motor. The specific design formula for the main insulation thickness d3 of the end region 3 is as follows:

[0063]

[0064] Where d1 is the main insulation thickness of slot region 1 of the stator coil, U N L1 represents the rated line voltage of the high-voltage motor, and L3 represents the length of the main insulation wrapping in end region 3.

[0065] The starting position of the main insulation wrapping in the end region 3 of the stator coil starts from the end of the main insulation in the slot exit region 2, and the end of the main insulation wrapping is the starting end of the lead wire insulation area wrapping; the wrapping thickness begins to decrease from the end of the main insulation in the slot exit region 2.

[0066] The main insulation thickness of the lead region 4 is d4, which is not greater than the main insulation thickness d3 of the end region 3, and the main insulation thickness of the lead region 4 is equal. The main insulation of the lead region 4 needs to withstand certain mechanical stress and thermal stress.

[0067] Specifically, the end of the end region 3 is the starting end of the main insulation wrapping of the lead region 4. The main insulation of the lead region 4 needs to withstand mechanical stress and thermal stress. The thickness d4 of the main insulation of the lead region 4 is not less than 2mm and the thickness d4 is not greater than the thickness d3 of the main insulation of the end region 3.

[0068] The experiment of this invention takes a 10kV high-voltage motor as an example. The average value of the stator coil power frequency breakdown voltage is increased from 75kV to 91kV, an increase of 24%, which greatly improves the overall electrical strength of the stator coil and the service life of the unit.

[0069] The technical solution proposed in this invention is based on theoretical calculations and statistical analysis of a large amount of scientific research experimental data. It has been practically applied to dozens of high-voltage motor products. According to the stress factors such as electrical stress, thermal stress and mechanical stress actually borne by different parts of the high-voltage motor stator coil, combined with the rated operating voltage of the unit, a refined design with different main insulation thicknesses is carried out for the slot region 1, slot outlet region 2, end region 3 and lead wire region 4 of the stator coil. This creates a flexible main insulation structure for high-voltage motor stator coils that is clear in principle, simple in structure, convenient in manufacturing process, and practical and efficient.

[0070] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention without creative effort should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A flexible main insulation structure of a high-voltage electrical machine stator coil comprising a stator conductor (5) and a main insulation layer outside it, characterized in that, The main insulation layer is divided into a groove area (1), a groove outlet area (2), an end area (3) and a lead area (4) connected in sequence, the main insulation thickness of the groove area (1) is d1, the main insulation thickness d1 of the groove area (1) is thinned, and the main insulation thickness of the groove area (1) is equal; The main insulation thickness of the groove outlet area (2) is d2, the main insulation thickness d2 of the groove outlet area (2) gradually increases and then gradually decreases from the end of the groove area (1), and d2 is not less than d1; The main insulation thickness of the end area (3) is d3, the main insulation thickness d3 of the end area (3) is thinned, and the main insulation thickness d3 of the end area (3) is linearly thinned from the end of the groove outlet area (2); the main insulation thickness d3 of the front end of the end area (3) is greater than the main insulation thickness d1 of the groove area (1), and the main insulation thickness d3 of the end of the end area (3) is less than the main insulation thickness d1 of the groove area (1); The main insulation thickness of the lead area (4) is d4, d4 thickness is not greater than the main insulation thickness d3 of the end area (3), and the main insulation thickness of the lead area (4) is equal; The main insulation wrapping length of the slot part region (1) is L1, L1 is longer than L0 of the stator core by Lx, the starting position of the main insulation wrapping of the slot exit part region (2) is Lx away from the end of the stator core, Lx increases with the increase of the rated voltage U of the high-voltage motor N . The Lx is determined according to the different rated voltage values of the motor, and the specific design formula is as follows: ； ； Lx is the length of the stator core from one end to the main insulation of the slot region (1), U N U is the rated line voltage of the high-voltage motor The units of d1, d2, d3, d4, L1 and Lx are all millimeters (mm).

2. A flexible main insulation structure for a high voltage machine stator coil according to claim 1, characterized in that, The design formula of the main insulation thickness d1 of the groove area (1) is as follows: ； ； Wherein, K is valued according to the motor operating characteristics and insulation life requirements, the value range is 2.6-3.3, U N is the rated line voltage value of the high-voltage motor.

3. A flexible main insulation structure for high voltage electrical machine stator coils according to claim 1, characterized in that, The main insulation wrapping length of the groove outlet area (2) is L2, L2 is prolonged with the increase of the rated voltage of the high-voltage motor, and the specific design formula of the wrapping length range L2 is as follows: ； ； wherein U N is the rated line voltage of the high-voltage machine, and L2 is in millimeters (mm).

4. A flexible main insulation structure for high voltage machine stator coils as defined in claim 1, wherein, The end of the end area (3) is the main insulation wrapping starting end of the lead area (4), the main insulation of the lead area (4) needs to bear mechanical stress and thermal stress, the main insulation thickness d4 of the lead area (4) is not less than 2mm, and d4 thickness is not greater than the main insulation thickness d3 of the end area (3).

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