A motor stator ventilation test experiment table

Abstract

The application discloses a motor stator ventilation test experiment table, which comprises pipes I, II, III and IV; the pipe I is provided with a horn at the port; the pipe I is connected with the pipe II; a stator mold card is arranged between the pipe II and the pipe III; the pipe III is connected with the pipe IV; the pipe IV is connected with a switching pipe; the switching pipe is connected with a centrifugal fan; and the centrifugal fan is driven by a dragging motor. The motor stator ventilation test experiment table can be designed with different stator mold cards for different motors, so as to realize the measurement of parameters such as the thermal resistance of the insulation layer, the axial and radial thermal resistance of the core laminations and the thermal resistance of the slot wedge under the conditions of natural convection and forced air cooling, and provide basic data for motor temperature field simulation and prediction. Meanwhile, the implementation effects of different types of cooling schemes of the stator core and the coil can be verified.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric machines, and relates to a heat dissipation design of an electric machine, in particular to an electric machine stator ventilation test experiment table. BACKGROUND

[0002] In the design of an electric machine, heat design is very important, and good heat dissipation is a necessary condition for stable operation of the electric machine. Generally, the coil nested on the stator of the electric machine is the main heat source, the surface of the coil is wrapped with an insulating material, and the structure of the stator of the electric machine requires dip paint and drying treatment to ensure that the insulation is not damaged. The above process makes the thermal resistance of the insulating layer, the axial and radial thermal resistance of the core laminations, and the thermal resistance of the slot wedge unknown. At the same time, there are problems in the heat dissipation optimization of the stator core laminations and the coil under forced ventilation. Generally, the heat exchange process can be simulated by simulation technology, but the thermal resistance values of the components are the basic data for simulation calculation, and therefore an experimental device is urgently needed to measure the thermal resistance and other related parameters of the components of the stator of the electric machine, so as to optimize the simulation technology and improve the accuracy of the heat design of the electric machine, and lay a foundation for the heat dissipation design of the electric machine. SUMMARY

[0003] The application aims to provide an electric machine stator ventilation test experiment table, which is used to measure the thermal resistance of the insulating layer, the axial and radial thermal resistance of the core laminations, the thermal resistance of the slot wedge and other parameters, optimize the simulation technology, and verify the implementation effect of different types of cooling schemes of the stator core and the coil.

[0004] The application is implemented by using the following technical scheme:

[0005] An electric machine stator ventilation test experiment table comprises a pipeline I, a pipeline II, a pipeline III, and a pipeline IV. A horn is mounted at the port of the pipeline I. The pipeline I is connected with the pipeline II. A stator mold card is connected between the pipeline II and the pipeline III. The pipeline III is connected with the pipeline IV. The pipeline IV is connected with an adapter pipe. The adapter pipe is connected with a centrifugal fan. The centrifugal fan is driven by a drag motor. A Pitot tube I is mounted on the side wall of the pipeline II. The Pitot tube I is connected with a pressure measuring element I. A Pitot tube II is mounted on the side wall of the pipeline IV. The Pitot tube II is connected with a pressure measuring element II. Core laminations are arranged in the stator mold card. The core laminations are located in a heat preservation material. Temperature sensors are embedded in the heat preservation material. The drag fan is connected with a power supply through a frequency converter. The coils on the core laminations are respectively electrically connected with the power supply.

[0006] When working, air enters the passage from the horn, flows through pipe I, and then realizes pressure measurement in pipe II, that is, the average pressure of the passage section is measured through the Pitot tube I and the pressure measuring element, and the air volume of the forced ventilation into the stator module card can be obtained from the average pressure of the section and the section area. The air takes the heat generated by the heating of the stator module card into pipe III, pipe IV and the adapter pipe, and the pressure is continuously measured at the middle section of pipe IV. The pressure measurement method is consistent with the pressure measurement method in pipe II. The static pressure values on both sides of the stator module card can be used to calculate the resistance of the stator module card, and the dynamic pressure on both sides can also be used to verify whether the flow is conservative, that is, whether the sealing is reliable. Finally, the air is discharged into the atmosphere from the fan exhaust pipe of the centrifugal fan. If the temperature distribution of the core laminations and the coil under natural convection conditions is measured, only the power supply on both sides of the coil is connected to heat the stator module card, and only the temperature is monitored; if the temperature distribution of the core laminations and the coil under forced ventilation conditions is measured, the power supply on both sides of the coil is connected to heat the stator module card, and at the same time, the air volume of the centrifugal fan is controlled through the frequency converter, and the pressure and temperature parameters are monitored according to the experimental conditions to achieve the experimental purpose.

[0007] Further preferably, the inner wall of the stator module card is provided with a heat preservation partition plate. The stator module card is provided with baffles in front and back, and the core laminations are supported on the front and back baffles; the heat preservation material is located between the front and back baffles.

[0008] The purpose of designing this experimental platform is to measure the temperature, flow, air pressure and other parameters of the coil heating ventilation experimental device, and to compare with the simulation results to obtain the core loss, slot wedge thermal resistance, insulation layer contact equivalent thermal resistance, and core temperature gradient. Basic principle: after the experimental device is ventilated stably, the coil is heated, and the heat is calculated q = I 2 R , the average temperature of the coil in the stator module card is measured T cu , the surface temperature of the coil outer insulation layer T s , according to the formula The equivalent thermal resistance between the coil and the core is calculated. For different stator mold cards and insulation structures, the test is carried out one by one to obtain the equivalent thermal resistance of the insulation layer and other parameters under different insulation structures. The experimental database is perfected. The application of experimental data, the core loss, slot wedge thermal resistance, insulation layer contact equivalent thermal resistance and other parameters obtained by experiment are applied to the simulation calculation of stator mold card temperature rise, the temperature distribution obtained by simulation is compared with the experimental temperature distribution, and the temperature rise simulation precision is improved. Then the above optimized temperature rise simulation technology method is applied to the temperature rise simulation of the whole motor, and the temperature rise simulation precision of the motor product is further improved. The motor stator ventilation test experimental table realizes the accumulation of equivalent thermal resistance and other parameters of different stator mold cards and different insulation structures, and gradually perfects the experimental database. These experimental data are mainly used as the key basic data support of motor temperature rise simulation.

[0009] The motor stator ventilation test experimental table is designed reasonably, different stator mold cards can be designed for different motors, the insulation layer thermal resistance, axial and radial thermal resistance of the core laminations, thermal resistance of the slot wedge and other parameters under natural convection and forced air cooling are measured, and the basic data for motor temperature field simulation prediction are provided. At the same time, the implementation effect of different types of cooling schemes of the stator core and the coil can be verified, and the motor stator ventilation test experimental table has good practical application value. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The figure shows the top view of the experimental table according to the present application.

[0011] Figure 2 The figure shows the front view of the experimental table according to the present application.

[0012] Figure 3 The figure shows the cross-sectional view of the stator mold card of embodiment 1 of the present application.

[0013] Figure 4 The figure shows the overall schematic diagram of the stator mold card of embodiment 1 of the present application.

[0014] Figure 5 The figure shows the isometric view of the core laminations I (rectangular cross section) in the stator mold card of embodiment 1 of the present application.

[0015] Figure 6 The figure shows the cross-sectional view of the stator mold card of embodiment 2 of the present application.

[0016] Figure 7 The figure shows the isometric view of the core laminations II (fan ring cross section) in the stator mold card of embodiment 2 of the present application.

[0017] In the figure: 1 - bell mouth, 2 - pipe I, 3 - pipe II, 4 - pressure measuring element I, 5 - Pitot tube I, 6 - stator die card, 7 - bracket, 8 - pipe III, 9 - baffle, 10 - pipe IV, 11 - pressure measuring element II, 12 - Pitot tube II, 13 - adapter pipe, 14 - centrifugal fan, 15 - power cord hole, 16 - drag motor, 17 - fan exhaust pipe, 18 - frequency converter, 19 - power supply, 20 - foot cup, 21 - stator die card flange, 22 - thermal insulation partition, 23 - thermocouple outlet hole, 24 - coil I, 25 - core sheet I, 26 - thermal insulation material, 27 - slot wedge, 28 - wiring hole, 29 - stator core ventilation hole, 30 - core sheet II, 31 - coil II, 32 - air gap plate card. DETAILED DESCRIPTION

[0018] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] A motor stator ventilation test bench, comprising pipe I 2, pipe II 3, pipe III 8, pipe IV 10, stator die card 6, centrifugal fan 14, drag motor 16 and other components.

[0020] As shown in Figure 1 , 2 , the pipe I 2 port is provided with a bell mouth 1, the pipe I 2 is connected to the pipe II 3, the pipe II 3 and the pipe III 8 are connected by the stator die card 6, the two ends of the stator die card 6 are connected to the pipe II 3 and the pipe III 8 by the stator die card flange 21 and bolts. The pipe III 8 is connected to the pipe IV 10, the pipe IV 10 is connected to the adapter pipe 13, the adapter pipe 13 is connected to the centrifugal fan 14, the exhaust port of the centrifugal fan 14 is provided with a fan exhaust pipe 17, and the centrifugal fan 14 is driven by the drag motor 16.

[0021] As shown in Figure 1 , 2 , the pipe II 3 side wall is provided with a Pitot tube I 5, and the Pitot tube I 5 is connected to a pressure measuring element I 4; the pipe IV 10 side wall is provided with a Pitot tube II 12, and the Pitot tube II 12 is connected to a pressure measuring element II 11. In addition, the Pitot tube I 5 and the Pitot tube II 12 are not limited to being arranged on one side of the pipe II 3 and the pipe IV 10, and the pressure measuring element I 4 and the pressure measuring element II 11 include but are not limited to a micro-pressure gauge.

[0022] The main body of the motor stator ventilation test platform is a stator mold card 6. The stator mold card 6 is a replaceable component, and can be customized according to actual needs to be suitable for different motors. The material and shape of the stator mold card 6 are not limited in the embodiment. A heat insulation partition plate 22 is arranged on the inner wall of the stator mold card 6. Front and rear baffles 9 are arranged in the stator mold card 6. A power line hole 15 is arranged on the bottom plate of the stator mold card 6 outside the front and rear baffles. A core lamination is arranged in the stator mold card 6 and supported on the front and rear baffles 9. The core lamination is located in the heat insulation material 26. The heat insulation material 26 is located between the front and rear baffles 9. A temperature sensor is embedded in the heat insulation material 26. The temperature sensor is a thermocouple. The power line of the thermocouple is led out through a thermocouple outlet hole 23 in the side wall of the stator mold card 6 to realize the temperature test of each point in the stator mold card 6.

[0023] As shown in Figure 1 , 2 , the drag fan 16 is connected to the power supply 19 through the frequency converter 18 to control the rotation speed of the centrifugal fan 14 to control the air volume of the centrifugal fan 14. The coils on the core lamination are electrically connected to the power supply 19 at both ends. The pipeline I 2, the pipeline II 3, the pipeline III 8, the pipeline IV 10, the stator mold card 6 and the centrifugal fan 14 are located on the respective supports 7. The bottom plate of the support 7 is provided with a foot cup 20 to meet the height adjustment needs of the equipment.

[0024] In operation, as shown in Figure 1 , air enters the channel from the horn mouth 1, flows through the pipeline I 2, and then measures the pressure in the pipeline II 3, that is, the average pressure of the channel cross section is measured through the Pitot tube I 5 and the pressure measuring element 4. The average pressure of the cross section and the cross-sectional area can be used to obtain the air volume of the channel. Thus, the air volume of the forced ventilation when entering the stator mold card 6 is obtained. The air carries the heat generated by the heating of the stator mold card 6 into the pipeline III 8, the pipeline IV 10 and the adapter pipe 13. The pressure is continuously measured at the middle cross section of the pipeline IV 10. The pressure measurement method is consistent with the pressure measurement method in the pipeline II 3. The static pressure values on the front and rear sides of the stator mold card 6 can be used to calculate the resistance of the stator mold card 6. The dynamic pressure on both sides can also be used to verify whether the flow is conservative, that is, whether the sealing reliability is reliable. Finally, the air is discharged into the atmosphere from the fan exhaust pipe 17 of the centrifugal fan 14.

[0025] Example 1

[0026] As shown in Figure 3 , Figure 4 and Figure 5As shown, it is one of the stator die cards 6 of the motor stator ventilation test bench, the core laminations are rectangular cross-section core laminations 125, coil 124 is embedded in the slot wedge 27 on the upper surface of the core laminations 125, and the wire holes 28 are provided at both ends of the coil 124; the upper part of the stator die card 6 is a space through the front and back (i.e. the left and right and below of the core laminations 125 are filled with thermal insulation materials, and the upper part is used for cold air to pass through). The surface of the stator die card 6 is immersed in paint, and the thermocouple is arranged in the desired position in advance, and the wire of the thermocouple is stretched out through the thermocouple outlet hole 23 to connect the temperature collector.

[0027] During the experiment, the stator die card 6 is connected between the pipeline Ⅱ 3 and the pipeline Ⅲ 8 through the stator die card flange 21, and the air tightness of the test bench device is carefully checked. If the temperature distribution of the core laminations 125 and the coil 124 and other components under the condition of natural convection is measured, only the power supply on both sides of the coil 124 is connected through the wire hole 28 to heat the stator die card 6, and only the temperature is monitored; if the temperature distribution of the core laminations 125 and the coil 124 and other components under the condition of forced ventilation is measured, only the power supply on both sides of the coil 124 is connected through the wire hole 28 to heat the stator die card 6, and at the same time, the air volume of the centrifugal fan 14 is controlled through the frequency converter 18, and the pressure and temperature parameters are monitored according to the experimental conditions to achieve the experimental purpose.

[0028] Example 2

[0029] As Figure 6 and Figure 7As shown, this is another type of stator template 6 for a motor stator ventilation test bench. The core laminations are core laminations II 30 with a fan-shaped cross-section. A coil II 31 is embedded in the slot wedge 27 on the inner ring surface of the core lamination II 30. The coil II 31 has wiring holes 28 at both ends. An air gap plate 32 is provided outside the inner ring surface of the core lamination II 30. The cross-section of the core lamination II 30 in the stator template 6 is filled with insulation material 26 (i.e., the two cavities at the front and rear of the stator template 6 are not interconnected). Unlike in embodiment 1, the core lamination II 30 has stator core ventilation holes 29, and the air gap plate 32 can simulate an air gap ventilation structure. The surface of the stator template 6 is impregnated with paint, and thermocouples are pre-positioned in the required positions. The thermocouple wires extend through the thermocouple outlet holes 23 to connect to the temperature acquisition device. During the experiment, the stator mold 6 is connected between pipe II 3 and pipe III 8 via stator mold flange 21, and the airtightness of the experimental setup is carefully checked. If measuring the temperature distribution of components such as core lamination II 30 and coil II 31 under natural convection conditions, the power supply is connected only to both sides of coil II 31 through wiring hole 28 to heat the stator mold 6, and only the temperature is monitored. If measuring the temperature distribution of components such as core lamination II 30 and coil II 31 under forced ventilation conditions, the power supply is connected only to both sides of coil II 30 through wiring hole 28 to heat the stator mold 6. Simultaneously, the airflow of centrifugal fan 14 is controlled by frequency converter 18, and pressure and temperature parameters are monitored simultaneously according to the experimental conditions to achieve the experimental objective.

[0030] In addition, if the air gap plate 32 is removed, air will only pass through the stator ventilation holes. By changing parameters such as air volume, ventilation hole position, number of ventilation holes, and ventilation hole size, the influence of different cooling schemes on the temperature rise of the stator coil can be verified. At the same time, the influence of parameters such as insulation layer thickness, material, slot wedge thickness, and material on the coil temperature rise can be studied.

[0031] In Examples 1 and 2, the surfaces of coil I 24 and coil II 31 are wound with an insulating layer. The materials used for the coils and surface insulation, core laminations I 25 and II 30, and slot wedge 27 are the same as those used in actual motors, and are treated with impregnation and drying. The connections between pipes and between pipes and stator molds are all bolted flange connections, and the flanges have high-elasticity sealing gaskets in the middle to ensure the sealing of the experimental platform.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the embodiments of the present invention have been described in detail, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A test bench for stator ventilation of an electric motor, comprising pipe I (2), pipe II (3), pipe III (8), and pipe IV (10); characterized in that: The port of pipe I (2) is equipped with a flared mouth (1), pipe I (2) is connected to pipe II (3), stator mold (6) is connected between pipe II (3) and pipe III (8), pipe III (8) is connected to pipe IV (10), pipe IV (10) is connected to adapter pipe (13), adapter pipe (13) is connected to centrifugal fan (14), centrifugal fan (14) is driven by drive motor (16); Pitot tube I (5) is installed on the side wall of pipe II (3), and the Pitot tube I (5) is connected to pressure measuring element I (4); Pitot tube II (12) is installed on the side wall of pipe IV (10), and the Pitot tube II (12) is connected to pressure measuring element II (11); The stator mold (6) is provided with iron core laminations, which are located in the insulation material (26). A temperature sensor is embedded in the insulation material (26). The drive motor (16) is connected to the power supply (19) through the frequency converter (18), and the two ends of the coil on the iron core lamination are electrically connected to the power supply (19). The inner wall of the stator mold (6) is provided with a thermal insulation partition (22); The stator mold (6) is provided with baffles (9) at the front and back, and the core laminations are supported on the baffles (9) at the front and back; the insulation material (26) is located between the baffles (9) at the front and back. The core lamination is a rectangular core lamination I (25), and a coil I (24) is embedded in the slot wedge (27) on the upper surface of the core lamination I (25). The coil I (24) has wiring holes (28) at both ends. The upper part of the stator mold (6) is a through space. Alternatively, the core lamination is a fan-shaped annular core lamination II (30), and a coil II (31) is embedded in the slot wedge (27) on the inner annular surface of the core lamination II (30). The coil II (31) has wiring holes (28) at both ends. The core lamination II (30) has stator core ventilation holes (29). The stator mold (6) is filled with insulation material (26) in the cross section of the core lamination II (30). The inner annular surface of the core lamination II (30) is provided with an air gap plate (32). The stator module (6) has a power line hole (15) on the bottom plate outside the front and rear baffles. The two ends of the stator mold (6) are connected to pipe II (3) and pipe III (8) respectively through stator mold flange (21).

2. The motor stator ventilation test bench according to claim 1, characterized in that: The pipes I (2), II (3), III (8), IV (10), stator mold (6) and centrifugal fan (14) are located on their respective supports (7); the bottom plate of the support (7) is provided with cup feet (20).

3. The motor stator ventilation test bench according to claim 1, characterized in that: The temperature sensor is a thermocouple, and the power line of the thermocouple passes through the thermocouple outlet hole (23) located on the side wall of the stator mold (6).

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