Design method of oil-immersed high-temperature high-speed motor

Abstract

The application discloses a design method of an oil-immersed high-temperature high-speed motor, and belongs to the technical field of motor design. The method is as follows: the insulation temperature resistance, wire load, magnetic load and permanent magnet working temperature are pre-acquired, and magnetic pressure drop calculation is carried out; the armature diameter, axial length, phase winding and main reactance and leakage reactance parameters, no-load performance and load performance, related loss, core and casing temperature in thermal steady state, and permanent magnet temperature are sequentially calculated; the permanent magnet temperature is compared by difference until the temperature error reaches the allowable range; the winding and insulation temperature is calculated; the winding and insulation temperature is compared by difference until the winding and insulation temperature is lower than the preset insulation temperature resistance; and the motor efficiency is calculated. The application can check the motor winding temperature, avoids motor overheating and burning caused by excessively high temperature rise, fully considers the operation characteristics of the high-temperature high-speed motor, and has a guiding role for the scheme design of the oil-immersed high-temperature high-speed motor.

Description

Technical Field

[0001] This invention relates to a design method for an oil-immersed high-temperature high-speed motor, belonging to the field of motor design technology. Background Technology

[0002] Electric motors convert electrical energy into mechanical energy and are commonly used actuators in industrial production and daily life. However, for special applications such as high-temperature working environments and high-speed, high-power performance requirements, oil-immersed high-temperature, high-speed motors are necessary. Currently, most designs for oil-immersed high-temperature, high-speed motors employ traditional motor design methods, failing to optimize and verify the design methods for the motor's operating characteristics, neglecting oil friction losses, and neglecting motor temperature calculations during the design process. This results in actual product performance not matching the design target, difficulty in achieving high-temperature, high-speed operation, and a high risk of motor overheating and burnout. Summary of the Invention

[0003] To address the problems existing in the background art, the present invention provides a design method for an oil-immersed high-temperature high-speed motor.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a design method for an oil-immersed high-temperature high-speed motor, the method comprising the following steps:

[0005] S1: Pre-test the insulation temperature resistance T0, linear load A, and magnetic load B of the oil-immersed high-temperature high-speed motor. δ Calculate the armature diameter D and axial length l of the oil-immersed high-temperature high-speed motor. ef ;

[0006] S2: Preset the operating temperature T1 of the permanent magnet of the oil-immersed high-temperature high-speed motor, and calculate the magnetic voltage drop;

[0007] S3: Phase winding R of an oil-immersed high-temperature, high-speed motor a Calculation of main reactance X m Parameters and leakage reactance X s Calculation of parameters;

[0008] S4: Calculate the no-load performance and load performance of the oil-immersed high-temperature high-speed motor;

[0009] S5: Perform stator winding copper loss P cu Stator core loss P core Permanent magnet eddy current loss P eddy And oil film loss P oil Calculation;

[0010] S6: Core and casing temperatures T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor shell Calculation;

[0011] S7: Permanent magnet temperature T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor mag Calculation;

[0012] S8: The permanent magnet temperature T at thermal steady state obtained in S7 mag The difference between the temperature of the permanent magnet and the preset temperature T1 in S2 is calculated. If the difference is greater than the allowable error range δ, the error is considered zero. error Then the preset permanent magnet temperature T1 will be updated to the permanent magnet temperature T calculated in S7 under thermal steady state. mag Repeat steps S4-S8 until the preset permanent magnet temperature T1 equals the permanent magnet temperature T at thermal steady state. mag The error between them reaches the allowable range δ error At this point, the electromagnetic-temperature coupling design of the oil-immersed high-temperature high-speed motor is completed;

[0013] S9: Temperature T of windings and insulation during thermal steady-state testing of an oil-immersed high-temperature high-speed motor. coil Calculation;

[0014] S10: The temperature T of the winding and insulation under thermal steady state obtained from S9. coil Compared with the insulation temperature resistance T0 pre-selected by S1, if the temperature T of the winding and insulation in thermal steady state is... coil If the insulation temperature resistance is not lower than the preset temperature T0, then a new line load A' and / or a new magnetic load B should be pre-selected. δ ', and the new linear load A' and the new magnetic load B δ The product of ' is less than the pre-selected line load A and magnetic load B in S1. δ The product of the product is repeated in steps S2-S9 until the temperature T of the winding and insulation at thermal steady state is reached. coil The insulation temperature resistance T0 is lower than the preset value.

[0015] S11: Calculate the efficiency η of the oil-immersed high-temperature high-speed motor.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] Compared to traditional motor design methods, this invention calculates motor oil friction losses and considers the bidirectional coupling of temperature rise and electromagnetic inductance in oil-immersed high-temperature high-speed motors. The design process takes into account both the influence of temperature on the motor's electromagnetic characteristics and the temperature of the motor windings, thus preventing overheating and burnout due to excessive temperature rise. It fully considers the operating characteristics of high-temperature high-speed motors and provides guidance for the design of oil-immersed high-temperature high-speed motors. Attached Figure Description

[0018] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] A design method for an oil-immersed high-temperature high-speed motor, the method comprising the following steps:

[0021] S1: Based on the relevant specifications of the oil-immersed high-temperature high-speed motor, such as rated power P, rated speed n, rated torque, and rated voltage, pre-select the insulation temperature resistance T0, line load A, and magnetic load B of the oil-immersed high-temperature high-speed motor. δ Calculate the armature diameter D and axial length l of the oil-immersed high-temperature high-speed motor. ef ;

[0022] The armature diameter D and axial length l ef The calculation formula is as follows:

[0023]

[0024] In formula (1):

[0025] n is the rated speed of the motor;

[0026] P is the rated power of the motor;

[0027] α' p This is the calculated pole arc coefficient for the motor;

[0028] K nm The air gap magnetic field waveform coefficient of the motor;

[0029] K dp This represents the winding coefficient of the motor.

[0030] S2: After determining the armature diameter D and axial length l of the oil-immersed high-temperature high-speed motor ef Based on this, the operating temperature T1 of the permanent magnet of the oil-immersed high-temperature high-speed motor is preset, and the magnetic voltage drop of various parts such as stator teeth, stator yoke, rotor yoke, and air gap is calculated using the traditional magnetic circuit method motor design process.

[0031] During this process, the pole slot fit and outer diameter D of the oil-immersed high-temperature high-speed motor were determined. o Stator tooth volume V t Stator yoke volume V y Permanent magnet volume V pmStructural parameters such as the number of turns per phase winding N, and the magnetic flux density B of the stator teeth. t Stator yoke magnetic flux density B y Magnetic flux density B of rotor yoke r Performance parameters, etc.

[0032] S3: Based on the relevant design parameters, design the phase winding R of the oil-immersed high-temperature high-speed motor. a Calculation of main reactance X m Parameters and leakage reactance X s Calculation of parameters;

[0033] S301: Calculate phase winding R a The formula is as follows:

[0034]

[0035] In formula (2):

[0036] ρ is the resistivity of the conductor;

[0037] N is the number of turns of the coil per phase of the motor;

[0038] l end This refers to the length of the winding end.

[0039] r1 is the radius of the wire;

[0040] 2a represents the number of parallel branches;

[0041] S302: Calculate the main reactance X m Parameters and leakage reactance X s The formula for the parameter is as follows:

[0042]

[0043] In formula (3):

[0044] f is the electrical frequency of the motor during operation;

[0045] μ0 is the vacuum permeability;

[0046] P' is the number of pole pairs of the motor;

[0047] q is the number of stator slots of the motor;

[0048] m is the number of phases of the motor;

[0049] τ is the polar moment;

[0050] δ ef This is the air gap length;

[0051] λ s Leakage permeability.

[0052] S4: Calculate the no-load performance (mainly no-load back EMF) and load performance (mainly current under rated load conditions) of the oil-immersed high-temperature high-speed motor.

[0053] S401: The formula for calculating the no-load back EMF E is as follows:

[0054] E = 4.44fK dp K nm Nφ δ (4)

[0055] In equation (4):

[0056] φ δ The magnetic flux passing through the motor coil;

[0057] S402: Calculate the current i under rated load conditions a The calculation formula is as follows:

[0058]

[0059] S5: Perform stator winding copper loss P cu Stator core loss P core Permanent magnet eddy current loss P eddy And oil film loss P oil Calculation;

[0060] S501: Calculate stator winding copper loss P cu The formula is as follows:

[0061] P cu =mi a 2 R a (6)

[0062] S502: Calculate stator core loss P core The formula is as follows:

[0063]

[0064] In equation (7):

[0065] P t For tooth core loss;

[0066] P y For yoke core loss;

[0067] K h These are material property coefficients related to hysteresis loss in core losses;

[0068] K e The material property coefficients related to eddy current losses in core losses;

[0069] K c This refers to the material property coefficients related to the additional losses in the core loss;

[0070] B t For the magnetic flux density of the teeth;

[0071] B y For the yoke magnetic flux density;

[0072] ρ core The density of the core material;

[0073] V t This refers to the volume of the stator teeth.

[0074] V y This refers to the volume of the stator yoke.

[0075] S503: Calculate the eddy current loss P of the permanent magnet eddy The formula is as follows:

[0076]

[0077] In equation (8):

[0078] B δ For magnetic load;

[0079] μ pm The permeability of a permanent magnet;

[0080] ρ pm The conductivity of the permanent magnet;

[0081] S504: Calculate oil friction loss P oil The formula is as follows:

[0082]

[0083] In equation (9):

[0084] μ oil The kinematic viscosity of the oil used in the machine;

[0085] R1 is the rotation radius of the motor;

[0086] ω0 is the angular velocity of the motor rotation.

[0087] S6: Core and casing temperatures T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor shell Calculation;

[0088] S601: Because the oil-immersed high-temperature high-speed motor operates under high-temperature conditions, the motor temperature needs to be calculated during the design process. When the oil-immersed high-temperature high-speed motor reaches thermal steady state, all the heat generated internally through losses is dissipated to the external environment through the casing, i.e.:

[0089] P cu +P core +P eddy +P oil =(T shell -T out )hS (10)

[0090] S602: Calculate the core and casing temperatures T of the motor under thermal steady-state conditions. shell The formula is as follows:

[0091]

[0092] In equation (11):

[0093] T out The ambient temperature;

[0094] h is the heat dissipation coefficient of the casing;

[0095] S represents the heat dissipation area of ​​the casing.

[0096] S7: Permanent magnet temperature T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor mag Calculation;

[0097] When the oil-immersed high-temperature high-speed motor reaches thermal steady state, all eddy current losses of the permanent magnet are transferred to the external environment through the core and casing, preventing the permanent magnet from heating up further. At this point, thermal equilibrium is reached, and the permanent magnet temperature T at the thermal steady state described in S7 is... mag The calculation formula is as follows:

[0098]

[0099] In equation (12):

[0100] k core The thermal conductivity of the core material;

[0101] A core This represents the cross-sectional area of ​​the heat conduction path.

[0102] D out This is the outer diameter of the motor core.

[0103] S8: The permanent magnet temperature T at thermal steady state obtained in S7 mag The difference between the temperature of the permanent magnet and the preset temperature T1 in S2 is calculated. If the difference is greater than the allowable error range δ, the error is considered zero. error (1℃), then update the preset permanent magnet temperature T1 to the permanent magnet temperature T calculated in S7 at thermal steady state. mag Repeat steps S4-S8 until the preset permanent magnet temperature T1 equals the permanent magnet temperature T at thermal steady state. mag The error between them reaches the allowable range δerror At this point, the electromagnetic-temperature coupling design of the oil-immersed high-temperature high-speed motor is completed;

[0104] S9: Temperature T of windings and insulation during thermal steady-state testing of an oil-immersed high-temperature high-speed motor. coil Calculation;

[0105] When an oil-immersed high-temperature high-speed motor operates in thermal steady state, the stator winding copper loss P cu All the heat generated is dissipated into the iron core through the heat conduction path, therefore the temperature T of the winding and insulation mentioned in S9 is... coil The calculation formula is as follows:

[0106]

[0107] In equation (13):

[0108] k coil The thermal conductivity of the winding;

[0109] A coil This represents the heat-conducting area of ​​the winding;

[0110] x represents the length of the heat conduction path of the copper loss, which is also the insulation thickness.

[0111] S10: The temperature T of the winding and insulation under thermal steady state obtained from S9. coil Compared with the insulation temperature resistance T0 pre-selected by S1, if the temperature T of the winding and insulation in thermal steady state is... coil If the insulation temperature resistance is not lower than the preset temperature T0, then a new line load A' and / or a new magnetic load B should be pre-selected. δ ', and the new linear load A' and the new magnetic load B δ The product of ' is less than the pre-selected line load A and magnetic load B in S1. δ The product of, i.e., A'B δ '<AB δ Or A'B δ <AB δ or AB δ '<AB δ The new line load A' is less than the line load A pre-selected in S1 and / or the new magnetic load B. δ 'Magnetic load B less than S1 pre-selected δ Repeat steps S2-S9 until the temperature T of the winding and insulation at thermal steady state is reached. coil The insulation temperature resistance T0 is lower than the preset value.

[0112] S11: Calculate the efficiency η of the oil-immersed high-temperature high-speed motor.

[0113] The efficiency η is calculated using the following formula:

[0114]

[0115] In equation (14):

[0116] P i This represents the input power of the motor.

[0117] Once the efficiency η of the oil-immersed high-temperature high-speed motor is calculated, the design of the oil-immersed high-temperature high-speed motor is completed, and the design results of the high-temperature high-speed motor can be obtained.

[0118] Example 1:

[0119] Taking an oil-immersed high-temperature high-speed motor with a rated power P = 1.5kW, a rated speed n = 9000r / min, a rated torque of 1.6Nm, and an operating ambient temperature of 120℃ as an example, the motor design method proposed in this invention will be explained.

[0120] Since the operating environment temperature is 120℃, insulation class H is selected, corresponding to a temperature resistance of 180℃.

[0121] S1: Pre-selected insulation temperature resistance T0 = 180℃, line load A = 400A / cm, and magnetic load B of the oil-immersed high-temperature high-speed motor. δ =1T, pre-select the calculated pole arc coefficient α' of the motor p =0.8, assuming a sinusoidal distribution of the air gap magnetic field, then K at this time nm =1.1, Pre-select the winding coefficient K of the motor dp =0.866, the length-to-diameter ratio of the motor is preset to 2, then substituting into equation (1) yields:

[0122]

[0123] Solving for:

[0124] D 2 l ef =3.335×10 -5

[0125] Given that the length-to-diameter ratio of the motor is pre-selected as 2, then:

[0126] D 2 l ef =2D 3 =3.335×10 -5

[0127] D = 0.026m

[0128] Adding a 2mm allowance, the armature diameter D = 28mm can be obtained.

[0129] Based on the motor's length-to-diameter ratio being pre-set to 2, the motor's axial length is calculated to be 56mm, which facilitates the calculation of the axial length l.ef =55mm.

[0130] S2: The operating temperature of the permanent magnet in the oil-immersed high-temperature high-speed motor is preset to T1 = 120℃, and the number of turns per phase coil of the oil-immersed high-temperature high-speed motor is determined to be N = 40. The conductor material is copper, then the resistivity of the conductor material copper is ρ = 0.019Ωmm. 2 / m; conductor radius r1=0.35mm; number of parallel conductor branches 2a=1; determine the winding end length L endf =0.025mm; Electrical frequency of the motor during operation f = 450Hz; Vacuum permeability μ0 = 4π × 10 -7 H / m; Number of pole pairs p' = 3; Number of stator slots q = 9; Number of phases m = 3; Pole pitch τ = 0.049m; Air gap length δ ef =1mm; leakage permeability λ s =0.035; Magnetic flux φ through the motor coil δ =4.2×10 -4 Wb;

[0131] S3: Phase winding R of an oil-immersed high-temperature, high-speed motor a Calculation of main reactance X m Parameters and leakage reactance X s Calculation of parameters;

[0132] Based on the obtained axial length l ef =0.055m, calculate the phase winding R a The process is as follows:

[0133]

[0134] Calculate the main reactance X m Parameters and leakage reactance X s The process for obtaining the parameters is as follows:

[0135]

[0136] Solving for:

[0137] X m =4.81Ω, X s =0.26Ω

[0138] S4: Calculate the no-load performance and load performance of the oil-immersed high-temperature high-speed motor;

[0139] The process of calculating the no-load back EMF E is as follows:

[0140] E = 4.44fK dp K nm Nφ δ

[0141] = 4.44 × 450 × 0.866 × 1.1 × 40 × 4.2 × 10 -4

[0142] =31.94V

[0143] Calculate the current i under rated load conditions. a The process is as follows:

[0144]

[0145] S5: Perform stator winding copper loss P cu Stator core loss P core Permanent magnet eddy current loss P eddy And oil film loss P oil Calculation;

[0146] S501: Calculate stator winding copper loss P cu The process is as follows:

[0147] P cu =mi a 2 R a =3i a 2 R a =3 × 15.62 2 ×0.159=120W

[0148] S502: Material characteristic coefficient K related to hysteresis loss in core loss. h =0.022; Material property coefficient K related to eddy current loss in core loss. e =1.075; Material property coefficient K related to additional losses in core loss. c =1.42; Tooth magnetic flux density B t =1.5T; yoke magnetic flux density B y =1.5T; density ρ of the core material core =7650kg / m 3 Stator tooth volume V t =8.79×10 -5 mm 3 Stator yoke volume V y =5.71×10 -5 mm 3 Then calculate the stator core loss P. core The process is as follows:

[0149]

[0150] S503: Magnetic load B of the motor δ=1T; Permeability μ of permanent magnet material pm =1.1 × 4π × 10 -7 H / m; electrical conductivity ρ of permanent magnet material pm =625000 simens / m; then calculate the eddy current loss P of the permanent magnet. eddy The formula is as follows:

[0151]

[0152] S504: Kinematic viscosity μ of internally filled oil oil =1.42×10 -11 m 2 / s; the motor's rotation radius R1 = 14mm; the motor's angular velocity ω0 = 942.5rad / s, then calculate the oil friction loss P. oil The formula is as follows:

[0153]

[0154] S6: The surface heat dissipation coefficient of the motor is h = 42.8 W / (m²). 2 (℃), the heat dissipation area of ​​the motor is S=0.225m². 2 After multiple iterations, the stator core and casing temperatures T in thermal steady state are obtained. shell =144℃,

[0155]

[0156] S7: Thermal conductivity k of the core material core = 42W / (m℃); heat conduction path cross-sectional area A core =0.974m 2 ; Outer diameter R of motor core out =0.052m; then the thermal steady-state temperature T of the permanent magnet can be calculated. mag =165℃:

[0157]

[0158] S8: The permanent magnet temperature T in thermal steady state magg The difference between the preset permanent magnet temperature T'1 = 120℃ and the preset permanent magnet temperature T'1 = 165℃ is 45℃, which is greater than 1℃. Therefore, the preset permanent magnet temperature T'1 = 165℃ is updated, and S4-S8 are repeated until the preset permanent magnet temperature and the permanent magnet temperature T'1 at thermal steady state are found. mag The error between them reaches the allowable range δ error Inside;

[0159] S9: Thermal conductivity K of the winding coil = 401W / (m℃); Radial heat conduction area A of the winding coil=0.974m 2 The thermal path length of the copper loss, i.e., the insulation thickness x = 1.26 × 10⁻⁶. -3 m. Then the winding and insulation temperature T can be calculated. coil The temperature is 192℃.

[0160]

[0161] S10: The temperature T of the winding and insulation under thermal steady state. coil Comparing the temperature of 192℃ with the pre-selected insulation temperature T0 = 180℃ in S1, it significantly exceeds the insulation temperature resistance.

[0162] Then a new line load A' = 330 A / cm is pre-calculated (from A and B). δ The combined effect of these factors determines the armature diameter D and axial length l of the motor. ef Therefore, it is necessary to consider A and B. δ The product of A and / or B is adjusted, thus allowing adjustment of A and / or B. δ Adjustments can be made as needed, and steps S2-S9 are repeated until the temperature T of the winding and insulation at thermal steady state is reached. coil The insulation temperature resistance T0 is lower than the preset value.

[0163] S11: Through the calculation of main dimensions and the iterative design process using the magnetic circuit method, the armature diameter D of the motor can be obtained as 28mm, and the axial length l ef =70mm, tooth magnetic flux density is 1.5T, yoke magnetic flux density is 1.5T. Motor copper loss P cu =94W, stator core loss P core =63W, rotor eddy current loss P eddy =26W, oil friction loss P oil =15W.

[0164] After multiple iterations, the stator core and casing temperatures T in thermal steady state were obtained. shell =128℃, the final steady-state operating temperature T of the permanent magnet mag =153℃, winding and insulation temperature T coil =168℃.

[0165] At this point, the winding and insulation temperature is 168℃, which is within the insulation temperature resistance range. Due to the motor's input power P... i =1500W, therefore, after calculation, the motor efficiency is 88.34%, all indicators meet the requirements, the winding and insulation temperature is 168℃, the permanent magnet temperature is 153℃, and it can operate normally under the condition of 120℃, realizing the design scheme of oil-immersed high temperature high speed motor.

[0166] During the design of the electromagnetic scheme for the motor, motor losses and temperature rise were calculated simultaneously, and an iterative design method was constructed to realize the electromagnetic-temperature rise coupled design process of the oil-immersed high-temperature high-speed motor, ultimately achieving the design of the oil-immersed high-temperature high-speed motor.

[0167] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0168] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A design method for an oil-immersed high-temperature high-speed motor, characterized in that: The method includes the following steps: S1: Pre-test the insulation temperature resistance T0, linear load A, and magnetic load B of the oil-immersed high-temperature high-speed motor. δ Calculate the armature diameter D and axial length l of the oil-immersed high-temperature high-speed motor. ef : S2: Preset the operating temperature T1 of the permanent magnet of the oil-immersed high-temperature high-speed motor, and calculate the magnetic voltage drop; S3: Phase winding R of an oil-immersed high-temperature, high-speed motor a Calculation of main reactance X m Parameters and leakage reactance X s Calculation of parameters; S4: Calculate the no-load performance and load performance of the oil-immersed high-temperature high-speed motor; S5: Perform stator winding copper loss P cu Stator core loss P core Permanent magnet eddy current loss P eddy And oil film loss P oil Calculation; S6: Core and casing temperatures T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor shell Calculation; S7: Permanent magnet temperature T during thermal steady-state testing of an oil-immersed high-temperature high-speed motor mag Calculation; S8: The permanent magnet temperature T at thermal steady state obtained in S7 mag The difference between the temperature of the permanent magnet and the preset temperature T1 in S2 is calculated. If the difference is greater than the allowable error range δ, the error is considered zero. error Then the preset permanent magnet temperature T1 will be updated to the permanent magnet temperature T calculated in S7 under thermal steady state. mag Repeat steps S4-S8 until the preset permanent magnet temperature T1 equals the permanent magnet temperature T at thermal steady state. mag The error between them reaches the allowable range δ error At this point, the electromagnetic-temperature coupling design of the oil-immersed high-temperature high-speed motor is completed; S9: Temperature T of windings and insulation during thermal steady-state testing of an oil-immersed high-temperature high-speed motor coil Calculation; S10: The temperature T of the winding and insulation under thermal steady state obtained from S9. coil Compared with the insulation temperature resistance T0 pre-selected by S1, if the temperature T of the winding and insulation in thermal steady state is... coil If the insulation temperature resistance is not lower than the preset temperature T0, then a new line load A' and / or a new magnetic load B should be pre-selected. δ ', and the new linear load A' and the new magnetic load B δ The product of ' is less than the pre-selected line load A and magnetic load B in S1. δ The product of the product is repeated in steps S2-S9 until the temperature T of the winding and insulation at thermal steady state is reached. coil The insulation temperature resistance T0 is lower than the preset value. S11: Calculate the efficiency η of the oil-immersed high-temperature high-speed motor.

2. The design method of an oil-immersed high-temperature high-speed motor according to claim 1, characterized in that: S1 describes the armature diameter D and axial length l ef The calculation formula is as follows: In formula (1): n is the rated speed of the motor; P is the rated power of the motor; α' p This is the calculated pole arc coefficient for the motor; K nm The air gap magnetic field waveform coefficient of the motor; K dp This represents the winding coefficient of the motor.

3. The design method of an oil-immersed high-temperature high-speed motor according to claim 2, characterized in that: S3 includes the following steps: S301: Calculate phase winding R a The formula is as follows: In formula (2): ρ is the resistivity of the conductor; N is the number of turns of the coil per phase of the motor; l end This refers to the length of the winding end. r1 is the radius of the wire; 2a represents the number of parallel branches; S302: Calculate the main reactance X m Parameters and leakage reactance X s The formula for the parameter is as follows: In formula (3): f is the electrical frequency of the motor during operation; μ0 is the vacuum permeability; P' is the number of pole pairs of the motor; q is the number of stator slots of the motor; m is the number of phases of the motor; τ is the polar moment; δ ef This is the air gap length; λ s Leakage permeability.

4. The design method of an oil-immersed high-temperature high-speed motor according to claim 3, characterized in that: S4 includes the following steps: S401: The formula for calculating the no-load back EMF E is as follows: E=4.44fK dp K nm Nφ δ (4) In equation (4): φ δ The magnetic flux passing through the motor coil; S402: Calculate the current i under rated load conditions a The calculation formula is as follows:

5. The design method of an oil-immersed high-temperature high-speed motor according to claim 4, characterized in that: S5 includes the following steps: S501: Calculate stator winding copper loss P cu The formula is as follows: P cu =mi a 2 R a (6) S502: Calculate stator core loss P core The formula is as follows: In equation (7): P t For tooth core loss; P y For yoke core loss; K h These are material property coefficients related to hysteresis loss in core losses; K e The material property coefficients related to eddy current losses in core losses; K c This refers to the material property coefficients related to the additional losses in the core loss; B t For the magnetic flux density of the teeth; B y For the yoke magnetic flux density; ρ core The density of the core material; V t This refers to the volume of the stator teeth. V y This refers to the volume of the stator yoke. S503: Calculate the eddy current loss P of the permanent magnet eddy The formula is as follows: In equation (8): B δ For magnetic load; μ pm The permeability of a permanent magnet; ρ pm The conductivity of the permanent magnet; S504: Calculate oil friction loss P oil The formula is as follows: In equation (9): μ oil The kinematic viscosity of the oil used in the machine; R1 is the rotation radius of the motor; ω0 is the angular velocity of the motor rotation.

6. The design method of an oil-immersed high-temperature high-speed motor according to claim 5, characterized in that: S6 includes the following steps: S601: When the oil-immersed high-temperature high-speed motor reaches thermal steady state, all the heat generated inside the motor through losses is dissipated to the external environment through the casing, that is: P cu +P core +P eddy +P oil =(T shell -T out )hS (10) S602: Calculate the core and casing temperatures T of the motor under thermal steady-state conditions. shell The formula is as follows: In equation (11): T out The ambient temperature; h is the heat dissipation coefficient of the casing; S represents the heat dissipation area of ​​the casing.

7. The design method of an oil-immersed high-temperature high-speed motor according to claim 6, characterized in that: The permanent magnet temperature T in thermal steady state as described in S7 mag The calculation formula is as follows: In equation (12): k core The thermal conductivity of the core material; A core This represents the cross-sectional area of ​​the heat conduction path. D out This is the outer diameter of the motor core.

8. The design method of an oil-immersed high-temperature high-speed motor according to claim 7, characterized in that: The temperature T of the winding and insulation described in S9 coil The calculation formula is as follows: In equation (13): k coil The thermal conductivity of the winding; A coil This represents the heat-conducting area of ​​the winding; x represents the length of the heat conduction path for copper losses.

9. The design method of an oil-immersed high-temperature high-speed motor according to claim 8, characterized in that: The formula for calculating the efficiency η mentioned in S11 is as follows: In equation (14): P i This represents the input power of the motor.

Images