Method for solving falling of magnetic slot wedge of alternating-current high-voltage motor

Abstract

The invention relates to the technical field of the machine manufacturing industry, in particular to a method for preventing a magnetic slot wedge of an alternating-current high-voltage motor from falling off. Installing an expansion filler strip and a magnetic slot wedge on the processed stator of the motor, and processing the expansion filler strip and the magnetic slot wedge; and carrying out vacuum paint dipping treatment on the treated motor stator. The vibration resistance of the magnetic slot wedge can be improved by upgrading the magnetic slot wedge and adding the expansion pad strip between the slot wedge and the coil, and then the magnetic slot wedge, the expansion pad and the coil are dipped in the insulating paint by using a vacuum paint dipping process; the gap between the magnetic slot wedge and the iron core and the gap between the expansion filler strip and the coil are further eliminated, the magnetic slot wedge, the expansion filler strip and the coil basically form a whole after the insulating paint is dried, the impact resistance of the magnetic slot wedge of the motor is improved, the service life is prolonged, and therefore the problem that a traditional slot wedge is prone to falling off is solved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical manufacturing industry, and in particular to a method for solving the problem of magnetic slot wedge falling of an AC high-voltage motor. Background Art

[0002] There are mainly two forms of slot wedges for high-voltage motors. One is made of non-magnetic bamboo wedges, epoxy glass cloth boards, etc., and the other is made of magnetic electrical steel and neodymium iron boron materials.

[0003] When the first method is adopted, the slot wedge has good insulation performance and mechanical strength, which can meet the basic requirements of motor operation. When the second method is adopted, since the slot wedge has high magnetic permeability and magnetic induction intensity, it can effectively improve the operating efficiency of the motor.

[0004] However, in the first method, the slot wedge will not affect the magnetic field or guide the direction of the magnetic field during the operation of the motor, so the motor efficiency is relatively low and the noise is relatively high. In the actual use of the second method, since the magnetic slot wedge is sensitive to ambient temperature, humidity and mechanical stress, the magnetic slot wedge often falls off, causing the stator and rotor to rub and damage the stator winding and core, and the magnetic powder after wear is difficult to clean. These defects and hidden dangers bury hidden dangers for the safe and stable operation of the motor. Summary of the invention

[0005] The purpose of the present invention is to provide a method for solving the problem of magnetic slot wedges falling off in AC high-voltage motors, aiming to solve the problem that traditional slot wedges are easy to fall off.

[0006] To achieve the above object, the present invention provides a method for solving the problem of magnetic slot wedge falling of an AC high voltage motor, comprising the following steps:

[0007] Pre-process the original slot wedges of the motor;

[0008] Installing the expansion pad strip and the magnetic slot wedge on the treated stator of the motor and treating it;

[0009] The treated motor stator is subjected to vacuum varnishing treatment.

[0010] Among them, "pre-processing the original slot wedge of the motor" includes:

[0011] Clean the stator coil slots after removing the original slot wedges of the motor;

[0012] Conduct resistance and withstand voltage tests on the cleaned motor stator.

[0013] Among them, in "installing the expansion pads and magnetic slot wedges on the treated stator of the motor and treating it", it includes:

[0014] Installing the expansion spacer strip and the magnetic slot wedge on the stator of the motor;

[0015] Clean the debris on the motor stator;

[0016] Electrically test the cleaned motor.

[0017] Among them, in “cleaning the debris on the motor stator”, the cleaning process is:

[0018] Use 25kV high voltage insulation live cleaning agent to clean the debris;

[0019] Use water-free compressed air ≤0.3Mp to blow away the residual cleaning agent and dry it in an oven.

[0020] Among them, in the process of “blowing out the residual cleaning agent with water-free compressed air ≤0.3Mp and drying in an oven”, the drying temperature is 120°C and the drying time is 2 hours.

[0021] Among them, in "Electrical testing of cleaned motors", include:

[0022] Wait until the motor cools down to ambient temperature and then re-measure the DC resistance.

[0023] Conducting stator winding leakage current and DC withstand voltage tests on the motor;

[0024] An AC withstand voltage test is performed on the motor.

[0025] The step of “performing vacuum varnish dipping treatment on the treated motor stator” includes:

[0026] Putting the motor stator into a vacuum varnishing tank for varnishing;

[0027] The motor stator after the varnish treatment is placed in an oven for drying.

[0028] The present invention provides a method for solving the problem of magnetic slot wedges falling off in AC high-voltage motors, comprising the following steps: pre-treating the original slot wedges of the motor; installing the expansion pads and magnetic slot wedges on the treated stator of the motor and treating them; and vacuum dipping the treated stator of the motor. The present invention can improve the vibration resistance of the magnetic slot wedges by upgrading the magnetic slot wedges and adding expansion pads between the slot wedges and the coils, and then use the vacuum dipping process to dip the magnetic slot wedges, expansion pads and coils into insulating paint. When the expansion pads are dipped into the insulating paint, the volume increases and expands, further eliminating the gaps between the magnetic slot wedges and the iron core, and between the expansion pads and the coils. After the insulating paint is dried, the magnetic slot wedges, expansion pads and coils basically form a whole, which improves the impact resistance of the magnetic slot wedges of the motor and prolongs the service life, thereby solving the problem of traditional slot wedges falling off easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic diagram of H-type material.

[0031] Figure 2 This is a schematic diagram of type B material.

[0032] Figure 3 It is a schematic diagram of the magnetic slot wedge and expansion pad part.

[0033] Figure 4 It is a schematic diagram of the vacuum dipping part.

[0034] Figure 5 The present invention provides a flow chart of a method for solving the problem of magnetic slot wedges falling off in an AC high voltage motor.

[0035] Figure 6 It is a flow chart for preprocessing the original slot wedge of the motor.

[0036] Figure 7 The invention is a flow chart of installing the expansion pad strip and the magnetic slot wedge on the stator of the processed motor and performing the processing.

[0037] Figure 8 It is a flow chart for cleaning the debris on the motor stator.

[0038] Fig. 9 is a flow chart for electrical testing of a cleaned motor.

[0039] Fig.10 The present invention is a flow chart of performing vacuum varnishing treatment on the treated motor stator.

[0040] In the figure: 1-vacuum pump, 2-stop valve, 3-stator, 4-vacuum varnish tank, 5-circulation pump pipeline, 6-circulation pump, 7-insulating varnish storage box;

[0041] 101- magnetic slot wedge, 102- expansion pad. DETAILED DESCRIPTION

[0042] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0043] See also Figures 1 to 10 The present invention provides a method for solving the problem of magnetic slot wedge falling of an AC high voltage motor, comprising the following steps:

[0044] S1 pre-processes the original slot wedge of the motor;

[0045] S11 cleans the stator 3 coil slots after removing the original slot wedges of the motor;

[0046] Specific, ready Figure 1 The magnetic slot wedge 101 in the motor is upgraded in material from Class B magnetic slot wedge 101 to Class H magnetic slot wedge 101, thereby increasing the high temperature resistance and vibration resistance of the slot wedge. The original slot wedge of the motor is removed and the debris in the stator 3 coil slot is cleaned up.

[0047] S12 performs resistance and withstand voltage tests on the cleaned motor stator 3.

[0048] Specifically, the cleaned motor stator 3 should be qualified in the DC resistance and withstand voltage tests.

[0049] S2: installing the expansion pad 102 and the magnetic slot wedge 101 on the treated stator 3 of the motor and performing treatment;

[0050] S21 installs the expansion pad 102 and the magnetic slot wedge 101 on the stator 3 of the motor;

[0051] Specifically, an expansion gasket 102 is installed on the coil in the stator 3 slot, and a magnetic slot wedge 101 is installed on the expansion gasket 102. During the installation process, check that the edge of the magnetic slot wedge 101 is not damaged and that the surface of the magnetic slot wedge 101 is substantially flush with the surface of the stator 3 core (the protruding portion of the core is less than 0.5 mm).

[0052] S22 cleans the debris on the motor stator 3;

[0053] S221 uses 25kV high voltage insulation live cleaning agent to clean the debris;

[0054] Specifically, after the expansion pad 102 and the magnetic slot wedge 101 are installed, the internal debris of the motor stator 3 is removed, and the powder of the magnetic slot wedge 101 is cleaned with a 25kV high-voltage insulation live cleaning agent.

[0055] S222 uses water-free compressed air ≤0.3Mp to blow away the residual cleaning agent and dry it in an oven.

[0056] The drying temperature is 120°C and the drying time is 2 hours.

[0057] Specifically, the residual cleaning agent is purged with water-free compressed air of ≤0.3 Mp and dried in an oven at a drying temperature of 120° C. for 2 hours.

[0058] S23 performs electrical testing on the cleaned motor.

[0059] S231 waits for the motor to cool down to the ambient temperature and then re-measures the DC resistance;

[0060] Specifically, the DC resistance measurement is carried out after the motor has cooled to ambient temperature. The difference between the DC resistance values ​​of each phase winding of a motor of 3000V and above or 100kW and above should not exceed 2% of the minimum value. If the neutral point is not brought out, the line resistance can be measured and the difference should not exceed 1%.

[0061] S232: performing stator 3 winding leakage current and DC withstand voltage tests on the motor;

[0062] Specifically, the stator 3 winding leakage current and the DC withstand voltage test voltage are 2.5Un, and the phase difference of the leakage current is not greater than 100% of the minimum value. No regulations are made for leakage currents below 20μA.

[0063] S233 performs an AC withstand voltage test on the motor.

[0064] Specifically, the AC withstand voltage of the stator 3 winding is 1.5Un, and there is no breakdown discharge phenomenon for 1 minute.

[0065] S3 performs vacuum varnishing treatment on the treated motor stator 3 .

[0066] S31: placing the motor stator 3 into a vacuum varnishing tank 4 for varnishing;

[0067] Specifically, the motor stator 3 is placed in the vacuum varnish dipping tank 4 with a hanging basket, and the lid of the varnish dipping tank is covered and locked. The stop valve 2 is opened, and the vacuum varnish dipping tank 4 is evacuated to a vacuum degree of ≤0.095Mpa by the vacuum pump 1. The water-soluble F-class insulating varnish is input from the insulating varnish storage box 7 into the varnish dipping tank through the circulating pump 6 in cooperation with the circulating pump pipeline 5. During the process of feeding the varnish, attention should be paid to maintaining the vacuum degree and temperature stable to avoid the formation of large bubbles. When the paint surface rises to about 30mm above the coil of the motor stator 3, the paint feeding is stopped, and the vacuum varnish dipping is maintained for 15-20 minutes.

[0068] S32: putting the motor stator 3 after the varnish treatment into an oven for drying.

[0069] Specifically, the vacuum is released, and the paint in the paint immersion tank is returned to the insulating paint storage box 7. The paint immersion tank is opened, the motor is lifted out, and then dried in an oven at a drying temperature of 145° C.-155° C. for 4 hours.

[0070] Implementation process:

[0071] Be prepared Figure 1 The magnetic slot wedge 101 in the embodiment is upgraded in terms of material, from a Class B magnetic slot wedge 101 to a Class H magnetic slot wedge 101, thereby increasing the high temperature resistance and vibration resistance of the slot wedge.

[0072] Remove the original slot wedges of the motor and clean up the debris in the stator 3 coil slot. The DC resistance and withstand voltage tests should be qualified.

[0073] Install expansion pads 102 on the coils in the slots of stator 3, and install magnetic slot wedges 101 on expansion pads 102. During the installation process, check that the edge of magnetic slot wedges 101 is not damaged, and the surface of magnetic slot wedges 101 is basically flush with the surface of stator 3 iron core (the protruding part of the iron core is less than 0.5mm). After installing expansion pads 102 and magnetic slot wedges 101, remove the debris inside the motor stator 3, clean the magnetic slot wedge 101 powder with 25kV high-voltage insulation live cleaning agent, and then blow the residual cleaning agent with ≤0.3Mp anhydrous compressed air and dry it in an oven at a drying temperature of 120℃ for 2 hours. After the motor has cooled to ambient temperature, the DC resistance is measured. The difference between the DC resistance values ​​of each phase winding of motors of 3000V and above or 100kW and above should not exceed 2% of the minimum value. If the neutral point is not brought out, the line resistance can be measured, and the difference should not exceed 1%; the stator 3 winding leakage current and DC withstand voltage test voltage are 2.5Un, the phase-to-phase difference of the leakage current is not greater than 100% of the minimum value, and no regulations are made for leakage currents below 20μA; the stator 3 winding AC withstand voltage is 1.5Un, and there is no breakdown discharge for 1 minute.

[0074] Put the motor stator 3 into the vacuum varnishing tank 4 ( Figure 4-4 ), cover the paint tank lid and lock it. Use a vacuum pump 1 ( Figure 4-1 )Evacuate the vacuum varnish tank 4 to a vacuum degree of ≤0.095Mpa, and input water-soluble F-class insulating varnish into the varnish tank. During the varnish input process, pay attention to maintaining the vacuum degree and temperature stable to avoid the formation of large bubbles. Wait until the paint surface rises to the motor stator 3 coil ( Figure 4-3 ) when it is about 30mm above the surface, stop feeding the paint and keep the vacuum immersion for 15-20 minutes. Then release the vacuum and put the immersion paint tank ( Figure 4-4 ) is returned to the insulating paint storage box 7 ( Figure 4-7 ), open the paint dipping tank, lift out the motor and dry it in an oven at a temperature of 145°C-155°C for 4 hours.

[0075] The method for solving the problem of magnetic slot wedge falling of AC high voltage motor provided by the present invention has the following beneficial effects:

[0076] 1. The present invention provides a method for solving the problem of magnetic slot wedges falling off in AC high-voltage motors, which enables the magnetic slot wedges to withstand higher temperatures and are not easily demagnetized or broken during motor operation.

[0077] 2. The present invention provides a method for solving the problem of magnetic slot wedges falling off in AC high-voltage motors. The method adds expansion pads between the magnetic slot wedges and the windings to maintain the tightness between the slot wedges and the iron core, thereby preventing the slot wedges from loosening and falling off due to vibration during the operation of the motor.

[0078] 3. The present invention provides a method for solving the problem of magnetic slot wedges falling off in AC high-voltage motors, which adopts a vacuum varnishing process to immerse insulating varnish into the gaps between windings, slot wedges and gaskets, thereby enhancing the overall stability of the windings and improving the impact resistance of the windings and slot wedges.

[0079] 4. The method provided by the present invention for solving the problem of magnetic slot wedges falling off in AC high-voltage motors reduces the number and quantity of slot wedges falling off, reduces the probability of motor operation damage, and improves the operating reliability of the unit.

[0080] 5. The method provided by the present invention for solving the problem of magnetic slot wedge falling of AC high-voltage motor reduces the number of times the motor needs to be disassembled and repaired, reduces the investment in manpower, financial resources, and material resources, and saves maintenance costs.

[0081] 6. The method provided by the present invention for solving the problem of magnetic slot wedge falling of AC high-voltage motors is based on the above points, which greatly improves the core market competitiveness of magnetic slot wedge motors.

[0082] The above disclosure is only a preferred embodiment of the method for solving the problem of magnetic slot wedge falling of AC high-voltage motors of the present invention. Of course, it cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for solving the problem of magnetic slot wedges falling off in AC high voltage motors, characterized in that: The following steps are involved: Pre-process the original slot wedges of the motor; Installing the expansion pad strip and the magnetic slot wedge on the treated stator of the motor and treating it; The treated motor stator is subjected to vacuum varnishing treatment.

2. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 1, characterized in that: In "Pre-treatment of the original slot wedge of the motor", it includes: Clean the stator coil slots after removing the original slot wedges of the motor; Conduct resistance and withstand voltage tests on the cleaned motor stator.

3. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 2, characterized in that: In "Installing the expansion spacer strips and magnetic slot wedges on the stator of the treated motor and treating it", including: Installing the expansion spacer strip and the magnetic slot wedge on the stator of the motor; Clean the debris on the motor stator; Electrically test the cleaned motor.

4. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 3, characterized in that: In "Cleaning the debris on the motor stator", the cleaning process is as follows: Use 25kV high voltage insulation live cleaning agent to clean the debris; Use water-free compressed air ≤0.3Mp to blow away the residual cleaning agent and dry it in an oven.

5. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 4, characterized in that: In the process of "blowing out the residual cleaning agent with water-free compressed air ≤ 0.3 Mp and drying in an oven", the drying temperature is 120°C and the drying time is 2 hours.

6. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 5, characterized in that: In "Electrical testing of cleaned motors", include: Wait until the motor cools down to ambient temperature and then re-measure the DC resistance. Conducting stator winding leakage current and DC withstand voltage tests on the motor; An AC withstand voltage test is performed on the motor.

7. The method for solving the problem of magnetic slot wedge falling of AC high voltage motor according to claim 6 is characterized in that: In "performing vacuum varnish dipping treatment on the treated motor stator", the method comprises: Putting the motor stator into a vacuum varnishing tank for varnishing; The motor stator after the varnish treatment is placed in an oven for drying.

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