CN112713676A - Optimization method for ventilation hole of axial variable-section stator of traction motor - Google Patents
Optimization method for ventilation hole of axial variable-section stator of traction motor Download PDFInfo
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- CN112713676A CN112713676A CN202011284697.1A CN202011284697A CN112713676A CN 112713676 A CN112713676 A CN 112713676A CN 202011284697 A CN202011284697 A CN 202011284697A CN 112713676 A CN112713676 A CN 112713676A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/20—Stationary parts of the magnetic circuit with channels or ducts for flow of cooling medium
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/24—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors with channels or ducts for cooling medium between the conductors
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
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Abstract
The invention belongs to the technical field of motors, and relates to an optimization method of an axial variable cross-section stator vent hole of a traction motor, which comprises the following steps: and axial uniform-section cylindrical ventilation holes are established on the stator iron core, and the temperature distribution rule is analyzed. The lowest temperature of the stator winding is taken as a target, the axial uniform-section cylindrical vent hole is changed into an axial unequal-section sectional cylindrical vent hole, and a local optimal scheme 1 is found; changing the axial unequal-section segmented cylindrical vent hole into an axial unequal-section continuous circular truncated cone vent hole, and searching a local optimal scheme 2; on the basis of the local optimal scheme 2, the diameter of the section of the vent hole is changed, and a local optimal scheme 3 is searched; on the basis of the local optimal scheme 3, the distance from the center of the vent hole to the axis of the motor is changed, and a local optimal scheme 4 is searched to serve as a global optimal scheme. According to the invention, by seeking a local optimal solution, a global optimal solution and an optimal stator ventilation structure, the temperature rise of the motor is effectively reduced.
Description
Technical Field
The invention belongs to the technical field of motors, and particularly relates to an optimization method for an axial variable-section stator vent hole of a traction motor.
Background
In recent years, the railway operation mileage in China is increasing continuously, and the development of high-speed railways puts higher requirements on the power quality and the operation safety of trains. The asynchronous traction motor is used as a core component of a high-speed train, has the advantages of simple structure, large overload capacity, convenience in maintenance and the like, and the performance of the asynchronous traction motor is directly related to the running safety of the high-speed railway. With the development of high-speed rail technology, the capacity and power density of a high-speed rail traction motor are larger and larger, and the following problems are that: the heating value of the motor is larger, the problem that the temperature rise of the motor is too high and the like is possibly faced, and the higher requirement is provided for the cooling and ventilating efficiency of the motor. In recent years, in the operation of the asynchronous traction motor of the high-speed motor train unit in China, more thermal problems occur: since the operation of CRH2-013A and CRH2-032A, in a traction transmission system, the fault caused by the high temperature of the motor accounts for 16.6% of the total fault, and the CRH2008 motor train unit also has the problem of overheating and burning of the traction motor, and the reasons for the above are found as follows: the motor temperature rise is too high due to unsmooth ventilation of the motor, so that the following effects are achieved: the temperature rise problem of the motor seriously threatens the safe operation of the train. Therefore, the ventilation structure of the motor stator is reasonably optimized, the utilization rate of the heat transfer medium of the motor is improved, and the effective reduction of the temperature rise of the motor (especially the temperature of the stator winding) is very important.
Disclosure of Invention
The invention provides an optimization method of an axial variable cross-section stator vent hole of a traction motor, which aims to solve the problems in the background technology.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for optimizing ventilation holes of an axial variable-section stator of a traction motor comprises the following steps:
step 1: evenly set up x axial uniform cross-section's cylindrical ventilation hole 1 along stator core 2's circumference, axial uniform cross-section's cylindrical ventilation hole 1's cross-sectional diameter is d0The distance from the center of the hole to the center of the motor shaft is r0Carrying out temperature field simulation on a motor model with a cylindrical vent hole 1 structure with x axial equal sections to obtain a temperature distribution rule of the motor model;
step 2: step 1 on the basis of the ventilation hole structure, the cylindrical ventilation hole 1 with the axial uniform section is modified into the segmented cylindrical ventilation hole with the axial unequal section, the aperture of the segmented cylindrical ventilation hole with the axial unequal section is sequentially and segmentally increased, and the minimum value of the aperture is dminThe maximum value of the pore diameter is dmax(ii) a Carrying out temperature field simulation on a motor model with a segmented cylindrical vent hole structure with axially unequal sections to obtain a temperature distribution rule of the motor model;
searching and determining a local optimal scheme 1 by taking the lowest temperature of the motor stator winding as a target;
and step 3: the minimum value of the aperture corresponding to the number of segments determined in the local optimum 1 is dminMaximum value of pore diameter dmaxOn the basis, the segmented cylindrical vent holes with the axial unequal sections are modified into continuous truncated cone-shaped vent holes with the axial unequal sections;
the diameter of the cross section of the continuous truncated cone-shaped vent hole with the axially unequal cross sections is dtComprises the following steps: diameter d of minor end of slave circular truncated coneminLinearly gradually changing to the diameter d of the large end of the circular truncated conemax；
Carrying out temperature field simulation on the motor model with the continuous truncated cone-shaped vent hole structure with the axially unequal cross sections, exploring the influence rule of the continuous truncated cone-shaped vent holes with the axially unequal cross sections on the motor temperature, and searching and determining a local optimal scheme by taking the lowest temperature of the motor stator winding as a target;
comparing the result determined in the step with the local optimal scheme 1, and determining a local optimal scheme 2 by taking the lowest temperature of the motor stator winding as a target;
and 4, step 4: on the basis of the local optimal scheme 2, the diameter of the section of the vent hole is changed;
carrying out temperature field simulation on a motor model structure with the diameter of the cross section of the vent hole changed, exploring the influence rule of the diameter change of the cross section of the vent hole on the motor temperature, and searching and determining a local optimal scheme 3 by taking the lowest temperature of a motor stator winding as a target;
and 5: on the basis of the local optimal scheme 3, the distance from the hole center of the vent hole to the center of the motor shaft is changed;
carrying out temperature field simulation on the motor model structure with the distance from the hole center of the vent hole to the center of the motor shaft changed, exploring the influence rule of the distance on the motor temperature, and finding a local optimal scheme 4 by taking the lowest temperature of the motor stator winding as a target;
and finally, determining the local optimal scheme 4 as a global optimal scheme.
On the basis of the technical scheme, the specific steps of the step 2 are as follows:
by the cross-sectional diameter d of the vent hole0As the center, a is the step length, x n sections of cylindrical ventilation holes are arranged on the stator core 2;
when n is an odd number, the number of the transition metal atoms,
the diameters of the n sections of cylindrical ventilation holes are respectively as follows: d0-(n-1)÷2×a，…，d0-k1÷2×a，…，d0-4÷2×a，d0-2÷2×a，d0，d0+2÷2×a，d0+4÷2×a，…，d0+k1÷2×a，…，d0+(n-1)÷2×a，
Wherein k is1＝2，4，…，n-1；
When n is an even number, the number of n,
the diameters of the n sections of cylindrical ventilation holes are respectively as follows: d0-(n-1)÷2×a，…，d0-k2÷2×a，…，d0-3÷2×a，d0-1÷2×a，d0+1÷2×a，d0+3÷2×a，…，d0+k2÷2×a，…，d0+(n-1)÷2×a，
Wherein k is2＝1，3，…，n-1；
The n-section cylindrical vent hole structure is constrained by the structure of the stator core 2;
the method comprises the steps of carrying out temperature field simulation on a motor model with an n-section cylindrical vent hole structure, exploring the influence rule of segmented cylindrical vent holes with axially unequal sections on the motor temperature, and searching and determining a local optimal scheme 1 by taking the lowest temperature of a motor stator winding as a target.
On the basis of the technical scheme, when the local optimal scheme determined in the step 3 is a continuous truncated cone-shaped vent hole structure with unequal axial cross sections, the specific steps in the step 4 are as follows:
the diameter d of the small end of the circular truncated cone of the continuous circular truncated cone-shaped vent hole with the axial unequal cross sectionminLinearly gradually changing to the diameter d of the large end of the circular truncated conemaxBased on the structure of (1), the diameter of the cross section of the vent hole is changed by taking b as a step length to form m1A continuous truncated cone-shaped vent hole structure with axially unequal cross sections;
the diameter of the cross section of each vent hole is larger than 0, and the diameter of the cross section of each vent hole can ensure that x continuous round platform-shaped vent holes with unequal axial cross sections are uniformly arranged along the circumferential direction of the stator core 2;
the section diameter of the 1 st continuous round platform-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated conemin-k3X b linearly gradually changes to the diameter d of the large end of the circular truncated conemax-k3×b；
The section diameter of the continuous round platform-shaped vent hole structure with the 2 nd axial unequal section is as follows: diameter d of minor end of slave circular truncated conemin-(k3-1) x b linear gradual change to the diameter d of the large end of the circular truncated conemax-(k3-1)×b；
……
Kth3-1 the cross-sectional diameter of the axially non-uniform cross-sectional continuous truncated cone shaped vent structure is: diameter d of minor end of slave circular truncated conemin-2 x b linear gradual change to the diameter d of the large end of the circular truncated conemax-2×b；
Kth3Continuous truncated cone ventilation with axially unequal cross-sectionsThe cross-sectional diameter of the pore structure is: diameter d of minor end of slave circular truncated conemin-1 x b linear gradual change to the diameter d of the large end of the circular truncated conemax-1×b；
Kth3+1 the diameter of the section of the structure of continuous truncated cone-shaped ventilation holes with axially unequal sections is: diameter d of minor end of slave circular truncated coneminThe +1 x b is linearly gradually changed to the diameter d of the large end of the circular truncated conemax+1×b；
Kth3+2 the diameter of the section of the continuous round platform-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated coneminThe +2 x b linear gradual change is carried out to the diameter d of the large end of the circular truncated conemax+2×b；
……
M th1-1 (i.e. k)3X 2-1) the cross-sectional diameter of the continuous truncated cone-shaped vent hole structure with axially unequal cross-sections is: diameter d of minor end of slave circular truncated conemin+(k3-1) x b linear gradual change to the diameter d of the large end of the circular truncated conemax+(k3-1)×b；
M th1(i.e. k)3X 2) the cross-sectional diameter of the continuous truncated cone-shaped vent hole structure with axially unequal cross-sections is: diameter d of minor end of slave circular truncated conemin+k3X b linearly gradually changes to the diameter d of the large end of the circular truncated conemax+k3×b；
Wherein m is1＝k3×2，k3＝1，2，3，…，m1÷2；
M is1The structure of the continuous round table-shaped vent hole with axially unequal sections is constrained by the structure of the stator core 2;
for the compound having m above1Respectively carrying out temperature field simulation on motor models of continuous truncated cone-shaped vent hole structures with axially unequal sections, and exploring the influence rule of vent hole section diameter change on the motor temperature; and (3) searching and determining a local optimal scheme 3 by taking the lowest temperature of the motor stator winding as a target.
On the basis of the technical scheme, when the local optimal scheme 1 determined in the step 3 is a segmented cylindrical vent hole structure with an axially unequal cross section, the specific steps in the step 4 are as follows:
based on segmented cylindrical ventilation holes with axially unequal cross sectionsThe base, taking e as the step length, changes the diameter of the section of the vent hole to form m2A segmented cylindrical vent structure of axially unequal cross-section;
the diameter of the cross section of each vent hole is larger than 0, and the diameter of the cross section of each vent hole can ensure that x segmented cylindrical vent holes with axially unequal cross sections are uniformly arranged along the circumferential direction of the stator core 2;
k is subtracted from the sectional diameter of each section of the 1 st axially unequal-section segmented cylindrical vent hole5×e；
The cross-sectional diameters of the 2 nd axially non-uniform cross-sectional segmented cylindrical vent sections are subtracted by (k)5-1)×e；
……
Kth5-1 the cross-sectional diameter of each segment of the axially unequal cross-sectional segmented cylindrical vent minus 2 × e;
kth51 × e is subtracted from the section diameter of each section of the segmented cylindrical ventilation hole with axially unequal sections;
kth5+1 adding 1 × e to the section diameter of each section of the segmented cylindrical vent hole with axially unequal sections;
kth5+2 sections of the segmented cylindrical ventilation holes with axially unequal sections plus 2 × e;
……
m th2-1 (i.e. k)5X 2-1) the diameters of the sections of the segmented cylindrical vent holes with axially unequal sections plus (k)5-1)×e；
M th2(i.e. k)5X 2) the diameter of the cross section of each section of the segmental cylindrical vent hole with axially unequal cross sections plus k5×e；
Wherein m is2＝k5×2，k5＝1，2，3，…，m2÷2；
M is2The segmented cylindrical vent hole structure with axially unequal sections is constrained by the structure of the stator core 2;
for the compound having m above2Respectively carrying out temperature field simulation on motor models with axially unequal cross-sections and segmented cylindrical vent hole structures, and exploring ventilationThe rule of the influence of the change of the hole section diameter on the motor temperature; and (3) searching and determining a local optimal scheme 3 by taking the lowest temperature of the motor stator winding as a target.
On the basis of the technical scheme, the specific steps of the step 5 are as follows:
c is taken as a step length, the distance from the hole center of the vent hole to the center of the motor shaft is changed, and p types of vent hole structures are formed;
the distance from the hole center of the vent hole to the center of the motor shaft is greater than D;
d is as follows: the sum of the distance D1 from the bottom of the stator groove to the center of the motor shaft and the radius of the large end of the section of the vent structure (namely the position where the diameter of the section in the vent structure is the largest) determined by the local optimal scheme 3;
the distance from the hole center of the vent hole to the center of the motor shaft is smaller than D';
the D' is: the difference between the radius D2 of the stator core 2 and the radius of the large end of the cross section of the vent hole structure determined by the local optimum 3;
namely, the distance from the hole center of the vent hole to the center of the motor shaft is between D and D';
the distance from the hole center of the 1 st ventilation hole structure to the center of the motor shaft is as follows: r is0-k4×c；
The distance from the hole center of the 2 nd ventilation hole structure to the center of the motor shaft is as follows: r is0-(k4-1)×c；
……
Kth4-the distance from the hole center of the 1 vent hole structure to the motor shaft center is: r is0-2×c；
Kth4The distance from the hole center of the ventilation hole structure to the center of the motor shaft is as follows: r is0-1×c；
Kth4The distance from the hole center of the +1 ventilation hole structures to the center of the motor shaft is as follows: r is0+1×c；
Kth4The distance from the hole center of the +2 types of vent hole structures to the center of the motor shaft is as follows: r is0+2×c；
……
P-1 (i.e., k)4X 2-1) kinds of vent holesThe distance from the center of the hole to the center of the motor shaft is as follows: r is0+(k4-1)×c；
P (i.e. k)4X 2) the distance from the hole center of the vent hole structure to the center of the motor shaft is: r is0+k4×c；
Wherein p ═ k4×2，k4＝1，2，3，…，p÷2；
The p types of vent hole structures are restricted by the structure of the stator core 2;
respectively carrying out temperature field simulation on the motor model with the p types of vent hole structures, and exploring the influence rule of the change of the distance from the hole center of the vent hole to the center of the motor shaft on the motor temperature; and (4) finding a local optimal scheme 4 by taking the lowest temperature of the stator winding of the motor as a target.
On the basis of the above technical solution, the step 2, the step 3, the step 4 and the step 5, which aims at the lowest temperature of the stator winding of the motor, means that: respectively carrying out temperature field simulation on motor models with different vent hole structures, respectively determining the highest temperatures of stator windings with different vent hole structures, then carrying out comparative analysis on the highest temperatures of the stator windings with different vent hole structures, and searching for a vent hole structure corresponding to the lowest temperature value in the highest temperatures.
The invention has the following beneficial technical effects:
the invention provides an optimization method of an axial variable-section stator vent hole of a traction motor, which can explore the influence rule of sectional cylindrical vent holes with axially unequal sections, continuous truncated cone-shaped vent holes with axially unequal sections, the diameter of the cross section of each vent hole and the distance from the hole center of each vent hole to the center of a motor shaft on the temperature of the motor, and obtain a global optimal solution by gradually searching a local optimal solution. The optimization method has important significance for optimizing the motor ventilation cooling structure and reducing the motor temperature rise.
Drawings
The invention has the following drawings:
FIG. 1 is a schematic flow chart of a method for optimizing axial variable cross-section stator ventilation holes of a traction motor according to the present invention;
FIG. 2 is a schematic view of the 1/2 motor configuration with axial uniform cross-section cylindrical stator vents;
FIG. 3 (a) is a schematic view of a section 3 of a cylindrical vent structure;
FIG. 3 (b) is a schematic view of a section 4 cylindrical vent structure;
FIG. 3 (c) is a schematic view of a section 5 cylindrical vent structure;
FIG. 4 is a schematic view of a continuous truncated cone-shaped vent hole with axially unequal cross-sections.
Reference numerals:
1. a cylindrical vent hole of axial uniform cross section; 2. a stator core is provided.
Detailed Description
In the following, preferred embodiments of the invention are explained in detail with reference to the drawings, which aim at reducing the stator winding temperature, without taking into account the mechanical strength of the machine.
The parameters involved in this example are: the number of the vent holes of the motor stator is as follows: x is 36; the section diameter d of the motor stator vent hole is changed along with the vent hole structure; the change step length of the section diameter of the motor stator vent hole is as follows: 2 mm; the distance from the hole center of the motor stator vent hole to the center of the motor shaft is r and is changed along with the vent hole structure; the distance change step length from the hole center of the motor stator ventilation hole to the center of the motor shaft is as follows: 10 mm.
The flow schematic diagram of the optimization method for the ventilation hole of the axial variable-section stator of the traction motor provided by the embodiment of the invention is shown in fig. 1, and specifically comprises the following steps:
step 1: cylindrical ventilation holes 1 with axial equal sections are formed along the stator core 2, and a motor model with the structure is subjected to temperature field simulation to obtain a temperature distribution rule.
The specific process is that, along the circumferential direction of the stator core 2, x is 36 cylindrical ventilation holes 1 with equal axial sections, and the section diameter of the cylindrical ventilation holes 1 with equal axial sections is d022mm, the distance from the center of the hole to the center of the motor shaft is r0257.5mm, the distance from the bottom of the stator slot to the center of the motor shaft is as follows: d1, the radius of the stator core 2 is: d2, as shown in FIG. 2. The motor model with the structure is subjected to temperature field simulation to obtain the temperature distribution rule, and the maximum temperature of the stator winding is 177.4 ℃.
Step 2: the cylindrical vent holes 1 with the axial equal sections are modified into segmented cylindrical vent holes with the axial unequal sections, the influence rule on the motor temperature is explored, and a local optimal scheme 1 is searched.
The specific process is as follows: the number of the vent holes is x-36, and the distance from the hole center to the motor shaft center is r0On the basis of 257.5mm,
by the cross-sectional diameter d of the vent hole0Taking a as a center, and respectively establishing 3 sections of cylindrical vent holes, 4 sections of cylindrical vent holes and 5 sections of cylindrical vent holes by taking a as a step length;
the diameters of the 3 sections of cylindrical ventilation holes are respectively as follows: d0-a、d0And d0+a；
The diameters of the 4 sections of cylindrical ventilation holes are respectively as follows: d0-1.5a、d0-0.5a、d0+0.5a and d0+1.5a；
The diameters of the 5 sections of cylindrical ventilation holes are respectively as follows: d0-2a、d0-a、d0、d0+ a and d0+2a；
When the diameter d of the cross section of the vent hole is used0When 3 sections of cylindrical vent holes, 4 sections of cylindrical vent holes and 5 sections of cylindrical vent holes are respectively established with a being 2mm as a step length, the diameters of the vent holes are respectively 20 mm-22 mm-24 mm, 19 mm-21 mm-23 mm-25 mm, 18 mm-20 mm-22 mm-24 mm-26 mm, and the structural schematic diagram of the 3 sections of cylindrical vent holes is shown in a graph (a) in fig. 3; the schematic structure of the 4-segment cylindrical vent hole is shown in figure 3 (b); the schematic structure of the 5-segment cylindrical vent hole is shown in fig. 3 (c).
Respectively carrying out temperature field simulation on a motor model with 3 sections of cylindrical vent hole structures, 4 sections of cylindrical vent hole structures and 5 sections of cylindrical vent hole structures, and exploring the influence rule of segmented cylindrical vent holes with unequal axial sections on the motor temperature;
the maximum temperature of the 3-section cylindrical ventilation hole stator winding is 174.8The maximum temperature of the 4-section cylindrical vent stator winding is 173.2 ℃, and the maximum temperature of the 5-section cylindrical vent stator winding is 173.1 ℃. Comparing temperature field simulation results of the cylindrical ventilation holes with different segment numbers, and finding and determining a local optimal scheme 1 by taking the lowest temperature of the motor stator winding as a target; the local optimal scheme 1 can be obtained as a 5-section cylindrical vent hole structure, and the specific parameters are as follows: the number of the vent holes is x-36, and the distance r from the center of the vent holes to the center of the motor shaft1257.5mm, cross-sectional diameter d of the vent hole1The segmentation is as follows: 18 mm-20 mm-22 mm-24 mm-26 mm.
And step 3: on the basis of the vent hole structure determined by the local optimal scheme 1, the segmented cylindrical vent holes with axially unequal sections are modified into continuous truncated cone-shaped vent holes with axially unequal sections, the influence rule on the motor temperature is explored, and the local optimal scheme 2 is searched.
The specific process is as follows: the 5 sections of cylindrical vent holes with unequal axial sections are modified into continuous truncated cone-shaped vent holes with unequal axial sections, as shown in fig. 4, the parameters are as follows: the number of the vent holes is x equal to 36, and the distance r from the hole center to the motor shaft center2257.5mm, the diameter of the section of the vent hole is d2Comprises the following steps: the diameter of the small end of the circular truncated cone is linearly changed from 18mm to 26 mm. The motor model with the structure is subjected to temperature field simulation, and the influence rule of the continuous truncated cone-shaped ventilation holes with axially unequal sections on the motor temperature is explored; the maximum temperature of the stator winding of the continuous circular truncated cone-shaped vent hole is as follows: 172.4 ℃ lower than the maximum temperature of the 5-segment cylindrical vent stator winding by 0.7 ℃. And comparing simulation results of the two schemes, and searching a local optimal scheme 2 by taking the lowest temperature of the motor stator winding as a target to obtain a continuous circular truncated cone-shaped vent structure with the local optimal scheme 2 being an axial unequal section.
And 4, step 4: on the basis of the local optimal scheme 2, the diameter of the cross section of the vent hole is changed, the influence rule of the change of the diameter of the cross section of the vent hole on the temperature of the motor is explored, and a local optimal scheme 3 is searched.
The specific process is as follows: the section diameter range d of the vent hole of the continuous truncated cone-shaped vent hole structure with the axially unequal sections in the step 32On the basis ofb is 2mm as the step length, changes the ventilation hole section diameter, obtains the scheme and is:
scheme (1): cross-sectional diameter range d of vent hole3aComprises the following steps: linearly changing from the diameter of the small end of the circular truncated cone to the diameter of the large end of the circular truncated cone by 24 mm;
scheme (2): cross-sectional diameter range d of vent hole3bComprises the following steps: linearly changing from the diameter of the small end of the circular truncated cone to the diameter of the large end of the circular truncated cone by 22 mm;
respectively carrying out temperature field simulation on the structures of the scheme (1) and the scheme (2), and exploring to obtain the influence rule of the diameter change of the section of the vent hole on the temperature of the motor:
when the structure of the scheme (1) is adopted, the maximum temperature of the stator winding is 169.0 ℃, and the distance r from the center of the hole to the center of the motor shaft2＝257.5mm；
When the structure of the scheme (2) is adopted, the maximum temperature of the stator winding is 164.4 ℃, and the distance r from the center of the hole to the center of the motor shaft3＝257.5mm。
The method comprises the following steps of searching a local optimal scheme 3 by taking the lowest temperature of a motor stator winding as a target, wherein the parameters of the obtained local optimal scheme 3 are as follows: the number of the vent holes is x-36, and the distance r from the center of the vent holes to the center of the motor shaft3＝r2257.5mm, diameter range d of the section of the vent hole3bComprises the following steps: the diameter of the small end of the circular truncated cone is linearly changed from 14mm to 22 mm.
And 5: on the basis of the local optimal scheme 3, the distance from the hole center of the vent hole to the center of the motor shaft is changed, the influence rule of the distance on the motor temperature is explored, and the local optimal scheme 4 is searched.
The specific process is as follows: on the basis of the local optimal scheme 3, the distance from the hole center to the motor shaft center is changed by taking c as a step length of 10mm, so that the following scheme is obtained:
scheme (3): distance r from hole center to motor shaft center4a＝247.5mm；
Scheme (4): distance r from hole center to motor shaft center4b＝237.5mm；
Scheme (5): distance r from hole center to motor shaft center4c＝227.5mm。
Respectively carrying out temperature field simulation on the motor models with the structures of the scheme (3), the scheme (4) and the scheme (5), and exploring the influence rules of different structures on the motor temperature:
when the structure of the scheme (3) is adopted, the highest temperature of the stator winding is 167.9 ℃;
when the structure of the scheme (4) is adopted, the highest temperature of the stator winding is 164.4 ℃;
when the structure of the aspect (5) is adopted, the maximum temperature of the stator winding is 162 ℃.
A local optimal scheme 4 is searched as a global optimal scheme 4 by taking the lowest temperature of the motor stator winding as a target;
finally, determining the local optimal scheme 4 as a global optimal scheme: the number of the vent holes is x equal to 36, and the distance r from the hole center to the motor shaft center4c227.5mm, cross-sectional diameter range d of vent hole4bComprises the following steps: the diameter of the small end of the circular truncated cone is linearly changed from 14mm to 22 mm.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Those not described in detail in this specification are within the knowledge of those skilled in the art.
Claims (6)
1. The optimization method of the ventilation hole of the axial variable-section stator of the traction motor is characterized by comprising the following steps of:
step 1: evenly set up cylindrical ventilation hole (1) of x axial uniform cross-sections along stator core's (2) circumference, the cross-sectional diameter of cylindrical ventilation hole (1) of axial uniform cross-section is d0The distance from the center of the hole to the center of the motor shaft is r0Carrying out temperature field simulation on a motor model with a cylindrical vent hole (1) structure with x axial equal sections to obtain a temperature distribution rule of the motor model;
step 2: step 1, on the basis of the vent structure, the cylindrical vent (1) with the axial uniform section is modified into the segmented cylindrical vent with the axial unequal section, the hole diameter of the segmented cylindrical vent with the axial unequal section is sequentially increased in a segmented manner, and the minimum value of the hole diameter is dminThe maximum value of the pore diameter is dmax(ii) a Carrying out temperature field simulation on a motor model with a segmented cylindrical vent hole structure with axially unequal sections to obtain a temperature distribution rule of the motor model;
searching and determining a local optimal scheme 1 by taking the lowest temperature of the motor stator winding as a target;
and step 3: the minimum value of the aperture corresponding to the number of segments determined in the local optimum 1 is dminMaximum value of pore diameter dmaxOn the basis, the segmented cylindrical vent holes with the axial unequal sections are modified into continuous truncated cone-shaped vent holes with the axial unequal sections;
the diameter d of the cross section of the continuous truncated cone-shaped vent hole with the axially unequal cross sectionstComprises the following steps: diameter d of minor end of slave circular truncated coneminLinearly gradually changing to the diameter d of the large end of the circular truncated conemax；
Carrying out temperature field simulation on the motor model with the continuous truncated cone-shaped vent hole structure with the axially unequal cross sections, exploring the influence rule of the continuous truncated cone-shaped vent holes with the axially unequal cross sections on the motor temperature, and searching and determining a local optimal scheme by taking the lowest temperature of the motor stator winding as a target;
comparing the result determined in the step with the local optimal scheme 1, and determining a local optimal scheme 2 by taking the lowest temperature of the motor stator winding as a target;
and 4, step 4: on the basis of the local optimal scheme 2, the diameter of the section of the vent hole is changed;
carrying out temperature field simulation on the motor model structure with the diameter of the cross section of the vent hole changed, exploring the influence rule of the diameter change of the cross section of the vent hole on the motor temperature, and searching and determining a local optimal scheme 3 by taking the lowest temperature of a motor stator winding as a target;
and 5: on the basis of the local optimal scheme 3, the distance from the hole center of the vent hole to the center of the motor shaft is changed;
carrying out temperature field simulation on the motor model structure for changing the distance from the hole center of the vent hole to the center of the motor shaft, exploring the influence rule of the distance on the motor temperature, and finding a local optimal scheme 4 by taking the lowest temperature of the motor stator winding as a target;
and finally, determining the local optimal scheme 4 as a global optimal scheme.
2. The optimization method of the ventilation holes of the axial variable-section stator of the traction motor as claimed in claim 1, wherein the specific steps in the step 2 are as follows:
by the cross-sectional diameter d of the vent hole0As the center, a is the step length, x n sections of cylindrical ventilation holes are arranged on the stator core (2);
when n is an odd number, the number of the transition metal atoms,
the diameters of the n sections of cylindrical ventilation holes are respectively as follows: d0-(n-1)÷2×a，…，d0-k1÷2×a，…，d0-4÷2×a，d0-2÷2×a，d0，d0+2÷2×a，d0+4÷2×a，…，d0+k1÷2×a，…，d0+(n-1)÷2×a，
Wherein k is1＝2，4，…，n-1；
When n is an even number, the number of n,
the diameters of the n sections of cylindrical ventilation holes are respectively as follows: d0-(n-1)÷2×a，…，d0-k2÷2×a，…，d0-3÷2×a，d0-1÷2×a，d0+1÷2×a，d0+3÷2×a，…，d0+k2÷2×a，…，d0+(n-1)÷2×a，
Wherein k is2＝1，3，…，n-1；
The n-section cylindrical vent hole structure is constrained by the structure of the stator core (2);
the method comprises the steps of carrying out temperature field simulation on a motor model with an n-section cylindrical vent hole structure, exploring the influence rule of segmented cylindrical vent holes with axially unequal sections on the motor temperature, and searching and determining a local optimal scheme 1 by taking the lowest temperature of a motor stator winding as a target.
3. The optimization method of the ventilation hole of the axial variable-section stator of the traction motor as claimed in claim 1, wherein when the local optimal scheme determined in the step 3 is a continuous truncated cone-shaped ventilation hole structure with axially unequal sections, the specific steps in the step 4 are as follows:
the diameter d of the small end of the circular truncated cone of the continuous circular truncated cone-shaped vent hole with the axial unequal cross sectionminLinearly gradually changing to the diameter d of the large end of the circular truncated conemaxBased on the structure of (1), the diameter of the cross section of the vent hole is changed by taking b as a step length to form m1A continuous truncated cone-shaped vent hole structure with axially unequal cross sections;
the cross section diameter of the vent hole is larger than 0, and the cross section diameter of the vent hole can ensure that x continuous round table-shaped vent holes with unequal axial cross sections are uniformly arranged along the circumferential direction of the stator core (2);
the section diameter of the 1 st continuous round platform-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated conemin-k3X b linearly gradually changes to the diameter d of the large end of the circular truncated conemax-k3×b；
The section diameter of the continuous round platform-shaped vent hole structure with the 2 nd axial unequal section is as follows: diameter d of minor end of slave circular truncated conemin-(k3-1) x b linear gradual change to the diameter d of the large end of the circular truncated conemax-(k3-1)×b；
……
Kth3-1 the cross-sectional diameter of the axially non-uniform cross-sectional continuous truncated cone shaped vent structure is: diameter d of minor end of slave circular truncated conemin-2 x b linear gradual change to the diameter d of the large end of the circular truncated conemax-2×b；
Kth3The diameter of the section of the continuous circular truncated cone-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated conemin-1 x b linear gradual change to the diameter d of the large end of the circular truncated conemax-1×b；
Kth3+1 the diameter of the section of the structure of continuous truncated cone-shaped ventilation holes with axially unequal sections is: diameter d of minor end of slave circular truncated coneminThe +1 x b is linearly gradually changed to the diameter d of the large end of the circular truncated conemax+1×b；
Kth3+2 the diameter of the section of the continuous round platform-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated coneminThe +2 x b linear gradual change is carried out to the diameter d of the large end of the circular truncated conemax+2×b；
……
M th1-1 the cross-sectional diameter of the axially non-uniform cross-sectional continuous truncated cone shaped vent structure is: diameter d of minor end of slave circular truncated conemin+(k3-1) x b linear gradual change to the diameter d of the large end of the circular truncated conemax+(k3-1)×b；
M th1The diameter of the section of the continuous circular truncated cone-shaped vent hole structure with axially unequal sections is as follows: diameter d of minor end of slave circular truncated conemin+k3X b linearly gradually changes to the diameter d of the large end of the circular truncated conemax+k3×b；
Wherein m is1＝k3×2，k3＝1，2，3，…，m1÷2；
M is1The continuous truncated cone-shaped vent hole structure with axially unequal sections is constrained by the structure of the stator core (2);
for the compound having m above1Respectively carrying out temperature field simulation on motor models of continuous truncated cone-shaped vent hole structures with axially unequal sections, and exploring the influence rule of vent hole section diameter change on the motor temperature; and (3) searching and determining a local optimal scheme 3 by taking the lowest temperature of the motor stator winding as a target.
4. The optimization method of the ventilation holes of the axial variable-section stator of the traction motor as claimed in claim 1, wherein when the local optimal scheme determined in the step 3 is a segmented cylindrical ventilation hole structure with an axially unequal section, the specific steps in the step 4 are as follows:
based on the sectional cylindrical vent holes with different axial sections, e is taken as a step length, the diameter of the section of the vent hole is changed to form m2A segmented cylindrical vent structure of axially unequal cross-section;
the diameter of the cross section of the vent hole is larger than 0, and the diameter of the cross section of the vent hole can ensure that x segmented cylindrical vent holes with axially unequal cross sections are uniformly arranged along the circumferential direction of the stator core (2);
k is subtracted from the sectional diameter of each section of the 1 st axially unequal-section segmented cylindrical vent hole5×e；
The cross-sectional diameters of the 2 nd axially non-uniform cross-sectional segmented cylindrical vent sections are subtracted by (k)5-1)×e；
……
Kth5-1 the cross-sectional diameter of each segment of the axially unequal cross-sectional segmented cylindrical vent minus 2 × e;
kth51 × e is subtracted from the section diameter of each section of the segmented cylindrical ventilation hole with axially unequal sections;
kth5+1 adding 1 × e to the section diameter of each section of the segmented cylindrical vent hole with axially unequal sections;
kth5+2 sections of the segmented cylindrical ventilation holes with axially unequal sections plus 2 × e;
……
m th2-1 sectional diameters of segments of axially unequal cross-section segmented cylindrical vent plus (k)5-1)×e；
M th2The cross section diameters of all the sections of the segmented cylindrical vent holes with axially unequal cross sections are added with k5×e；
Wherein m is2＝k5×2，k5＝1，2，3，…，m2÷2；
M is2The segmented cylindrical vent hole structure with axially unequal sections is constrained by the structure of the stator core (2);
for the compound having m above2Respectively carrying out temperature field simulation on motor models of the segmented cylindrical vent hole structures with axially unequal sections, and exploring the influence rule of the diameter change of the vent hole sections on the motor temperature; and (3) searching and determining a local optimal scheme 3 by taking the lowest temperature of the motor stator winding as a target.
5. The optimization method of the ventilation holes of the axial variable-section stator of the traction motor as claimed in claim 1, wherein the specific steps in the step 5 are as follows:
c is taken as a step length, the distance from the hole center of the vent hole to the center of the motor shaft is changed, and p types of vent hole structures are formed;
the distance from the hole center of the vent hole to the center of the motor shaft is greater than D;
d is as follows: the sum of the distance D1 from the bottom of the stator groove to the center of the motor shaft and the radius of the large end of the section of the vent structure (namely the position where the diameter of the section in the vent structure is the largest) determined by the local optimal scheme 3;
the distance from the hole center of the vent hole to the center of the motor shaft is smaller than D';
the D' is: the difference between the radius D2 of the stator core (2) and the radius of the large end of the cross section of the vent hole structure determined by the local optimal scheme 3;
the distance from the hole center of the 1 st ventilation hole structure to the center of the motor shaft is as follows: r is0-k4×c；
The distance from the hole center of the 2 nd ventilation hole structure to the center of the motor shaft is as follows: r is0-(k4-1)×c；
……
Kth4-the distance from the hole center of the 1 vent hole structure to the motor shaft center is: r is0-2×c；
Kth4The distance from the hole center of the ventilation hole structure to the center of the motor shaft is as follows: r is0-1×c；
Kth4The distance from the hole center of the +1 ventilation hole structures to the center of the motor shaft is as follows: r is0+1×c；
Kth4The distance from the hole center of the +2 types of vent hole structures to the center of the motor shaft is as follows: r is0+2×c；
……
The distance from the hole center of the p-1 ventilation hole structure to the center of the motor shaft is as follows: r is0+(k4-1)×c；
The distance from the hole center of the p-th ventilation hole structure to the center of the motor shaft is as follows: r is0+k4×c；
Wherein p ═ k4×2，k4＝1，2，3，…，p÷2；
The p types of vent hole structures are restricted by the structure of the stator core (2);
respectively carrying out temperature field simulation on the motor model with the p types of vent hole structures, and exploring the influence rule of the change of the distance from the hole center of the vent hole to the center of the motor shaft on the motor temperature; and (4) finding a local optimal scheme 4 by taking the lowest temperature of the stator winding of the motor as a target.
6. The optimization method of the ventilation holes of the axial variable-section stator of the traction motor according to any one of claims 2 to 5, characterized in that: the step 2, the step 3, the step 4 and the step 5, which aim at the lowest temperature of the stator winding of the motor, means that: respectively carrying out temperature field simulation on motor models with different vent hole structures, respectively determining the highest temperatures of stator windings with different vent hole structures, then carrying out comparative analysis on the highest temperatures of the stator windings with different vent hole structures, and searching for a vent hole structure corresponding to the lowest temperature value in the highest temperatures.
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