Preparation method of motor winding with mixed insulating layer
By using a thinner insulation layer and ordinary insulation materials in the motor winding, the insufficient insulation performance requirements and high cost are solved in the motor tank inside and outside, and the high cost is achieved, and the high groove fullness and power density are improved.
Patent Information
- Application Number
- CN202410985325.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2024-12-10
AI Technical Summary
The thickness and materials of the insulating layers inside and outside the groove of the existing motor winding are the same, which cannot meet the needs of high groove fullness and high power density. At the same time, low dielectric constant insulation materials are expensive and difficult to reduce costs.
Use low dielectric constant material to thin the thickness of the insulating layer in the groove, combine ordinary insulating material outside the groove, select the appropriate thickness by calculating the average value of the local discharge starting voltage, and cure it after baking to form a mixed insulating layer to improve the groove Full rate and cost reduction.
It improves the slot fullness and power density of the motor, reduces the cost of insulating materials, and meets the needs of different insulation properties.
Smart Images
Figure CN119109268A_ABST
Abstract
Description
Technical Field
[0001] The patent of this invention relates to the field of motor technology, and specifically to a motor winding with a hybrid insulation layer for new energy vehicles. Background Art
[0002] With the continuous development of new energy vehicle technology, drive motors are required to have low volume, high power density, and high efficiency. For the winding insulation layer in the motor slot, the thinner the better, while meeting the insulation performance requirements, so as to increase the slot fill rate and thus improve the motor efficiency and power density. The low dielectric constant insulation materials currently developed on the market can control the thickness of the insulation layer within a relatively small range to meet the requirements of new energy motors, but the low dielectric constant insulation materials are expensive, several times that of ordinary insulation materials.
[0003] Currently, the thickness and material of the insulation layer inside and outside the motor winding slot are the same, which cannot meet the requirements of different insulation performance inside and outside the slot of high slot fill rate and high power density motors. Summary of the invention
[0004] The present invention provides a method for preparing a motor winding with a mixed insulation layer. Not only does the slot winding in the slot use a material with a low dielectric constant to reduce the thickness of the insulation layer to improve the motor slot fill rate, but ordinary insulation materials are also used as insulation materials for the slot winding outside the slot, which is arranged in a sufficient space outside the slot, thereby reducing costs and improving the motor power.
[0005] The technical solutions to the above problems are as follows:
[0006] A method for preparing a motor winding with a mixed insulation layer comprises the following steps:
[0007] S1, obtain copper flat wire;
[0008] S2, bending the copper flat wire according to the design shape of the winding to form a winding blank;
[0009] S3, calculate the average partial discharge inception voltage PDIV of the winding according to the rated voltage of the motor, the impulse voltage insulation level and the controller level number RMS , according to the average partial discharge inception voltage PDIV RMS The dielectric constant of the material is used to select the insulating material with low dielectric constant and the thickness of the ordinary insulating material;
[0010] S4, wrapping a low dielectric constant insulating material around a portion of the winding blank corresponding to the motor stator wire embedding slot, and wrapping the remaining portion of the winding blank with a common insulating material to obtain a semi-finished winding;
[0011] S5, baking the semi-finished winding, so that the low dielectric constant insulating material and the common insulating material are connected into one body, and the low dielectric constant insulating material and the common insulating material are respectively fixed into one body with the copper flat wire.
[0012] Furthermore, the partial discharge inception voltage PDIV RMS The calculation process is as follows:
[0013] DC bus voltage:
[0014] Peak voltage: u b =u dc ×of (2)
[0015] Peak-to-peak operating voltage: u p-p =2(u dc / (n-1)+u b ) (3)
[0016] Average partial discharge inception voltage:
[0017] In the above formula: u dc is the DC bus voltage, u N is the rated voltage of the motor; u b is the peak voltage, of is the peak, u p-p is the peak-to-peak value of the operating voltage, n is the number of levels of the controller, and EF is the partial discharge enhancement factor.
[0018] Furthermore, the thickness of the low dielectric constant insulating material and the ordinary insulating material is calculated according to the following formula:
[0019]
[0020] Where: t is the thickness of the insulating material; ε r is the relative dielectric constant of the material.
[0021] Furthermore, the low dielectric constant insulating material adopts PDM-ODA type PI insulating film, and the common insulating material adopts KAPTON-FN type PI insulating film.
[0022] Furthermore, the number of layers of low dielectric constant insulating material and common insulating material wrapped is two, wherein the thickness of the PDM-ODA type PI insulating film is 25um, and the thickness of the KAPTON-FN type PI insulating film is 50um.
[0023] In the present invention, after the low dielectric constant insulating material is wrapped around the portion of the winding blank corresponding to the motor stator wire embedding slot, this method improves the slot fill rate of the wire embedding slot on the basis of thinning the thickness of the insulation layer; therefore, the hybrid insulation layer motor winding prepared by this method has a high slot fill rate, which improves the power density and efficiency of the drive motor and reduces the cost of the insulation material. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Prepare a flow chart for motor windings with mixed insulation.
[0025] Figure 2 This is a structural diagram of a motor winding with a mixed insulation layer.
[0026] Markings in the attached drawings:
[0027] Winding blank 1, low dielectric constant insulating material 2, common insulating material 3. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention is described in more detail below in conjunction with the drawings in the embodiment of the present invention. The described embodiment is a part of the embodiment of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and cannot be simply understood as limitations on the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings:
[0029] like Figure 1 to Figure 2 As shown, a method for preparing a motor winding with a mixed insulation layer comprises the following steps:
[0030] S1, obtain the copper flat wire.
[0031] S2, bending the copper rectangular wire according to the designed shape of the winding to form a winding blank 1.
[0032] S3, calculate the average partial discharge inception voltage PDIV of the winding according to the rated voltage of the motor, the impulse voltage insulation level and the controller level number RMS , according to the average partial discharge inception voltage PDIV RMS And the dielectric constant of the material selects low dielectric constant insulating material and the thickness of ordinary insulating material.
[0033] The partial discharge inception voltage PDIV RMS The calculation process is as follows:
[0034] DC bus voltage:
[0035] Peak voltage: u b =u dc ×of (2)
[0036] Peak-to-peak operating voltage: u p-p =2(u dc / (n-1)+u b ) (3)
[0037] Average partial discharge inception voltage:
[0038] In the above formula: u dc is the DC bus voltage, u N is the rated voltage of the motor; u b is the peak voltage, of is the peak, u p-p is the peak-to-peak value of the operating voltage, n is the number of levels of the controller, and EF is the partial discharge enhancement factor.
[0039] The thickness of low dielectric constant insulating materials and ordinary insulating materials is calculated according to the following formula:
[0040]
[0041] Where: t is the thickness of the insulating material; ε r is the relative dielectric constant of the material.
[0042] S4, wrapping the low dielectric constant insulating material 2 on the portion of the winding blank 1 corresponding to the motor stator wire embedding slot, and wrapping the remaining portion of the winding blank with ordinary insulating material 3 to obtain a semi-finished winding.
[0043] The low dielectric constant insulating material 2 uses a PDM-ODA type PI insulating film, and the common insulating material 3 uses a KAPTON-FN type PI insulating film. The number of layers of the low dielectric constant insulating material and the common insulating material is two, wherein the thickness of the PDM-ODA type PI insulating film is 25um, and the thickness of the KAPTON-FN type PI insulating film is 50um.
[0044] S5, baking the semi-finished winding, so that the low dielectric constant insulating material is connected to the common insulating material as a whole, and the low dielectric constant insulating material and the common insulating material are fixed to the copper flat wire as a whole. The selected low dielectric constant insulating material has affinity with the common insulating material, and can be solidified into a whole after baking.
[0045] Implementation Cases:
[0046] According to the electromagnetic scheme of the motor design, the size of the copper flat wire winding is 5mm in width and 3mm in thickness, the rated voltage of the motor is 500V, the impulse voltage insulation level is Class B, and the controller level number is 2.
[0047] Copper wire drawing: The raw material copper rod is drawn to form a copper flat wire with a thickness of 3mm and a width of 5mm, and then annealed.
[0048] Bending: Bend the copper flat wire according to the design shape of the winding, usually into a hairpin shape.
[0049] The average value of the partial discharge inception voltage of the winding is PDIV RMS The calculation process is as follows:
[0050] DC bus voltage:
[0051] Peak voltage: u b =u dc ×of=675×0.5=337.5V
[0052] Peak voltage peak value: u p-p =2(u dc / (n-1)+u b )=2×(675 / (2-1)+337.5)=2025V
[0053] Average partial discharge inception voltage:
[0054] The low dielectric constant insulating material 2 uses PDM-ODA type PI insulating film, and the dielectric constant of PDM-ODA type PI insulating film is 1.4; the ordinary insulating material 3 uses KAPTON-FN type PI insulating film, and the dielectric constant of KAPTON-FN type PI insulating film is 2.8; these two materials have affinity and can be cured into a whole after baking. The calculation process of the thickness of the insulating material inside and outside the slot is as follows: The thickness of the low dielectric constant insulating material Thickness of common insulation materials
[0055] Wrapping: The selected wrapping rate is 3 / 2, which is equivalent to wrapping two layers of insulation film on the copper flat wire. Therefore, the thickness of the PDM-ODA type PI insulation film is 25um, and the thickness of the KAPTON-FN type PI insulation film is 50um.
[0056] Baking: The mixed insulation layer winding after wrapping is baked and cured in an oven. The curing temperature is controlled at 150-160℃ and the baking time is controlled at 2.5-3min to solidify the mixed insulation layers and adhere the insulation layer to the copper flat wire to improve the insulation performance.
[0057] The hybrid insulation layer winding prepared by the above method was subjected to a partial discharge starting voltage test. The sample was bent according to the requirements of GB / T5591.2-2017 and tested according to the standard GB / T 7354-2018. The test voltage rose at a rate of 25V / s. When the partial discharge amount was greater than 100pC, the partial discharge starting voltage of the winding was recorded. The partial discharge starting voltage measured by the test was 1250V, which was greater than the starting voltage of 1167V where partial discharge may occur when the motor is running, and met the use requirements.
[0058] The above is a detailed description of the present technical solution. It should be understood that due to the limitations of text and the diversity of technical solutions, technicians in this field can also implement the present technical solution by replacing the text, grammar or other equivalents of the present technical solution. Therefore, such replacements should be deemed to be within the scope of protection of this application.
Claims
1. A method for preparing a motor winding with a mixed insulation layer, comprising the following steps: S1, obtain copper flat wire; S2, bending the copper flat wire according to the design shape of the winding to form a winding blank; S3, calculate the average partial discharge inception voltage PDIV of the winding according to the rated voltage of the motor, the impulse voltage insulation level and the controller level number RMS , according to the average partial discharge inception voltage PDIV RMS The dielectric constant of the material is used to select the insulating material with low dielectric constant and the thickness of the ordinary insulating material; S4, wrapping a low dielectric constant insulating material around a portion of the winding blank corresponding to the motor stator wire embedding slot, and wrapping the remaining portion of the winding blank with a common insulating material to obtain a semi-finished winding; S5, baking the semi-finished winding, so that the low dielectric constant insulating material and the common insulating material are connected into one body, and the low dielectric constant insulating material and the common insulating material are respectively fixed into one body with the copper flat wire.
2. The method for preparing a motor winding with a mixed insulation layer according to claim 1, characterized in that: The partial discharge inception voltage PDIV RMS The calculation process is as follows: DC bus voltage: Peak voltage: u b =u dc ×of (2) Peak-to-peak operating voltage: u p-p =2(u dc / (n-1)+u b ) (3) Average partial discharge inception voltage: In the above formula: u dc is the DC bus voltage, u N is the rated voltage of the motor; u b is the peak voltage, of is the peak, u p-p is the peak-to-peak value of the operating voltage, n is the number of levels of the controller, and EF is the partial discharge enhancement factor.
3. The method for preparing a motor winding with a mixed insulation layer according to claim 1, characterized in that: The thickness of low dielectric constant insulating materials and ordinary insulating materials is calculated according to the following formula: Where: t is the thickness of the insulating material; ε r is the relative dielectric constant of the material.
4. The method for preparing a motor winding with a mixed insulation layer according to claim 1, characterized in that: The low dielectric constant insulating material adopts PDM-ODA type PI insulating film, and the common insulating material adopts KAPTON-FN type PI insulating film.
5. The method for preparing a motor winding with a mixed insulation layer according to claim 4, characterized in that: The number of layers of low dielectric constant insulating material and common insulating material wrapped is two, wherein the thickness of PDM-ODA type PI insulating film is 25um, and the thickness of KAPTON-FN type PI insulating film is 50um.