A moisture-removing device suitable for AC motor and a moisture-removing method for AC motor

Abstract

The present invention provides a dehumidification device suitable for an AC motor and a dehumidification method for an AC motor, wherein the dehumidification device comprises: a variable frequency power supply and a capacitor. The voltage waveform of the variable frequency power supply is a sine wave, and both the voltage and the frequency are adjustable. The variable frequency power supply is provided with an output display, and the output display is used to display output parameters; the capacitor is electrically connected to the variable frequency power supply and to the motor; the variable frequency power supply, the capacitor and the motor form a resonant circuit, and the iron core of the motor is heated by the resonant circuit to achieve dehumidification. The dehumidification method for an AC motor is to use the dehumidification device to dehumidify the motor. The present invention is used to improve the problem that the dehumidification effect of the existing dehumidification method is not ideal.

Description

Technical Field

[0001] The present invention relates to the field of motor moisture removal, and in particular to a moisture removal device suitable for an AC motor and a moisture removal method for an AC motor. Background Art

[0002] High-voltage and large-capacity AC motors, such as 6KV high-voltage and large-capacity motors, are greatly affected by weather changes, especially in harsh outdoor working environments. Due to long downtime for major and minor repairs, the insulation materials of the windings are easily affected by moisture. If they are put into operation without moisture removal, accidents may occur such as excessive leakage current and burning of the motor. At present, the commonly used moisture removal methods for severely damp large-capacity motors are as follows.

[0003] For example, a DC welding machine is used to pass a DC current through the winding to heat the resistor in the winding, thereby achieving the purpose of moisture removal. Generally, the DC resistance of each winding of a 6KV large-capacity motor is about 0.5 ohms. After passing the DC current, the heating power = I2×R. However, the disadvantages of this method are as follows: 1. Due to the small DC resistance of the winding, the winding is locally heated, the moisture removal time is long, and the effect is not good. 2. Due to the large DC current passed, the resistance is large when the welding in the winding is poor, and a high temperature may be generated locally, causing insulation damage, which may cause a fire in severe cases.

[0004] Alternatively, use 2-4 1000W baking lamps to heat and bake the stator winding to remove moisture. The disadvantages of this method are as follows: 1. This method can only be performed after the rotor is pulled out. 2. The heating area is uneven, the baking lamp needs to be fixed in position, the heating distance is too large, and the heating effect cannot be achieved. If the heating distance is too close, it is easy to overheat locally and damage the insulation. 3. The heat loss generated by the baking lamp is large, the effective heat energy utilization rate is not high, and the moisture removal time is long.

[0005] Alternatively, use a high-power fan to accelerate air circulation and blow out moisture. The disadvantages of this method are as follows: 1. This method can only be performed when the air environment humidity is good, and the deep insulation moisture is not completely driven out, and the effect is poor. 2. When the weather environment is bad, dust may enter the winding and affect safe operation. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the present invention provides a dehumidification device and a dehumidification method for an AC motor, so as to improve the problem that the dehumidification effect of the existing dehumidification method is not ideal.

[0007] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides a dehumidification device suitable for an AC motor, comprising: a variable frequency power supply and a capacitor. The voltage of the variable frequency power supply is a sine wave, and the voltage and frequency of the variable frequency power supply are adjustable. The variable frequency power supply is provided with an output display, and the output display is used to display output parameters; the capacitor is electrically connected to the variable frequency power supply and to the motor; the variable frequency power supply, the capacitor and the motor form a resonant circuit, and the iron core of the motor is heated by the resonant circuit to achieve dehumidification. The variable frequency power supply is provided with an input power switch, a running switch, and an output switch. The output parameters include: voltage, current, active power, and frequency.

[0008] In one embodiment of the present invention, the capacitor includes a series capacitor, and the series capacitor is connected in series with the motor.

[0009] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead and the third phase lead of the motor are respectively electrically connected to the second end of the variable frequency power supply.

[0010] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a triangle connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead of the motor is electrically connected to the second end of the variable frequency power supply.

[0011] In one embodiment of the present invention, the capacitor includes a parallel capacitor, and the parallel capacitor is connected in parallel with the motor.

[0012] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the parallel capacitor is electrically connected to the first phase lead of the motor, the second end of the parallel capacitor is electrically connected to the second phase lead and the third phase lead of the motor respectively, the first end of the parallel capacitor is electrically connected to the first end of the variable frequency power supply, and the second end of the parallel capacitor is electrically connected to the second end of the variable frequency power supply.

[0013] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a triangle connection method, the first end of the parallel capacitor is electrically connected to the first phase lead of the motor, the second end of the parallel capacitor is electrically connected to the second phase lead of the motor, the first end of the parallel capacitor is electrically connected to the first end of the variable frequency power supply, and the second end of the parallel capacitor is electrically connected to the second end of the variable frequency power supply.

[0014] In one embodiment of the present invention, the capacitor includes a series capacitor and a parallel capacitor, the series capacitor is connected in series with the motor, the parallel capacitor is connected in parallel with the motor, and the resonant circuit maintains an under-compensated state.

[0015] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead and the third phase lead of the motor are respectively electrically connected to the second end of the variable frequency power supply; the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, and the second end of the shunt capacitor is electrically connected to the second phase lead and the third phase lead of the motor.

[0016] In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a triangle connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead of the motor is electrically connected to the second end of the variable frequency power supply; the first end of the parallel capacitor is electrically connected to the first phase lead of the motor, and the second end of the parallel capacitor is electrically connected to the second phase lead of the motor.

[0017] The present invention also provides an AC motor dehumidification method implemented by the device, comprising the steps of: obtaining the motor terminal and relevant parameters of the motor; determining the connection relationship between the motor and the capacitor based on the relevant parameters of the motor, and electrically connecting the variable frequency power supply, the capacitor and the motor terminal according to the connection relationship; obtaining the initial value of the relevant temperature of the motor; connecting the input power of the variable frequency power supply, starting the variable frequency power supply, adjusting the output parameter of the variable frequency power supply so that the output parameter value is the initial value, and closing the output switch of the variable frequency power supply; adjusting the voltage value of the variable frequency power supply to the starting voltage value, adjusting the output frequency of the variable frequency power supply until the output frequency meets the frequency setting condition, and then increasing the output voltage of the variable frequency power supply until the output voltage meets the voltage setting condition, and dehumidifying the motor; obtaining the temperature rise value of the relevant temperature of the motor, and judging whether the temperature rise value exceeds the set threshold value; when the temperature rise value meets the set threshold value, continuing to dehumidify the motor until the insulation resistance of the motor meets the standard.

[0018] In one embodiment of the present invention, the initial value of voltage is zero, the initial value of current is zero, the initial value of active power is zero, and the initial value of frequency is 50 Hz.

[0019] In one embodiment of the present invention, after the step of continuing to dehumidify the motor until the insulation resistance of the motor meets the standard, the step also includes: adjusting the output parameter of the variable frequency power supply so that the output parameter value is an initial value; disconnecting the output switch of the variable frequency power supply, turning off the variable frequency power supply, and disconnecting the input power of the variable frequency power supply; removing the dehumidification device from the motor and restoring the normal wiring of the motor.

[0020] In one embodiment of the present invention, the connection relationship is parallel, series or series-parallel.

[0021] The invention is applicable to a moisture-removing device of an AC motor. A resonant circuit is formed by a variable frequency power supply, a capacitor and a motor. The hysteresis and eddy current losses generated by the resonant circuit in the iron core of the motor are used to heat the iron core, thereby achieving the purpose of moisture removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 It is a series resonant circuit in star connection;

[0024] Figure 2It is a series resonant circuit in a triangle connection;

[0025] Figure 3 It is a parallel resonant circuit in star connection;

[0026] Figure 4 It is a parallel resonant circuit in a triangle connection;

[0027] Figure 5 It is a series-parallel resonant circuit in star connection;

[0028] Figure 6 It is a series-parallel resonant circuit in a triangle connection;

[0029] Figure 7 is the schematic diagram of the resonant circuit;

[0030] Figure 8 for Figure 7 The corresponding vector graph;

[0031] Fig. 9 It is the equivalent circuit diagram of the series-parallel resonant circuit;

[0032] Fig.10 for Fig. 9 The corresponding vector diagram.

[0033] Component number description

[0034] 100, variable frequency power supply; 200, capacitor; 300, motor. DETAILED DESCRIPTION

[0035] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0036] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0037] See also Figures 1 to 6 The present invention provides a dehumidification device suitable for an AC motor, comprising: a variable frequency power supply 100 and a capacitor 200. The voltage and frequency of the variable frequency power supply 100 are adjustable, and an output display is provided on the variable frequency power supply 100, and the output display is used to display output parameters; the capacitor 200 is electrically connected to the variable frequency power supply 100 and to the motor 300; the variable frequency power supply 100, the capacitor 200 and the motor 300 constitute a resonant circuit, and the iron core of the motor 300 is heated by the resonant circuit to achieve dehumidification. The variable frequency power supply is provided with an input power switch, a running switch, and an output switch. The output parameters include: voltage, current, active power, and frequency.

[0038] The output power of the variable frequency power supply is: three-phase 380V+15% (or 220V+15%); rated output power is: not less than 8KVA, active power resolution is 0.01 kilowatt; rated output voltage is: 0-800 volts and continuously adjustable, display resolution is 0.1 volt; rated output current is: not less than 10 amps above 400 volts, not less than 20 amps at 400 volts and below. Display resolution is 0.01 amp; output frequency is: 40-800 Hz and continuously adjustable, display resolution is 0.1 Hz; output voltage and current waveforms are sine waves, and voltage waveform distortion does not exceed 1.5% (at rated voltage and frequency). The output voltage and current of the variable frequency power supply shall not be greater than the rated voltage and rated current of the motor.

[0039] In one embodiment of the present invention, the variable frequency power supply is provided with stop and live working indicator lights, wherein the stop indicator light is green and the live working indicator light is red.

[0040] The noise level of the variable frequency power supply is less than 60 decibels, and the output parameter display mode is LED digital tube or pointer meter with accuracy not less than 0.5 level, etc. The variable frequency power supply is also equipped with short circuit protection, overload protection, over-voltage protection, under-voltage protection, power component overheating protection, etc.

[0041] In one embodiment of the present invention, the capacitor 200 includes a series capacitor, and the series capacitor is connected in series with the motor 300 .

[0042] See also Figure 1 In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead and the third phase lead of the motor are respectively electrically connected to the second end of the variable frequency power supply.

[0043] See also Figure 2In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a triangle connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead of the motor is electrically connected to the second end of the variable frequency power supply.

[0044] In one embodiment of the present invention, the capacitor 200 includes a parallel capacitor, and the parallel capacitor is connected in parallel with the motor 300 .

[0045] See also Figure 3 In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, the second end of the shunt capacitor is electrically connected to the second phase lead and the third phase lead of the motor respectively, the first end of the shunt capacitor is electrically connected to the first end of the variable frequency power supply, and the second end of the shunt capacitor is electrically connected to the second end of the variable frequency power supply.

[0046] See also Figure 4 In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a delta connection method, the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, the second end of the shunt capacitor is electrically connected to the second phase lead of the motor, the first end of the shunt capacitor is electrically connected to the first end of the variable frequency power supply, and the second end of the shunt capacitor is electrically connected to the second end of the variable frequency power supply.

[0047] In one embodiment of the present invention, the capacitor 200 includes a series capacitor and a parallel capacitor, the series capacitor is connected in series with the motor 300, the parallel capacitor is connected in parallel with the motor 300, and the resonant circuit maintains an under-compensated state.

[0048] See also Figure 5 In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a star connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead and the third phase lead of the motor are respectively electrically connected to the second end of the variable frequency power supply; the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, and the second end of the shunt capacitor is electrically connected to the second phase lead and the third phase lead of the motor.

[0049] See also Figure 6In one embodiment of the present invention, the motor is a three-phase AC motor, the winding connection method of the three-phase AC motor is a delta connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead of the motor is electrically connected to the second end of the variable frequency power supply; the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, and the second end of the shunt capacitor is electrically connected to the second phase lead of the motor.

[0050] exist Figures 1 to 6 In the figure, ABC represents the three-phase leads of the motor, and LN represents the two ends of the variable frequency power supply. Figure 1-6 The corresponding relationship is: A is the first phase lead of the motor, B is the third phase lead of the motor, C is the second phase lead of the motor, L is the first end of the variable frequency power supply, and N is the second end of the variable frequency power supply. It should be noted that the above correspondence is only for a better understanding of the technical solution and does not play a limiting role. That is, the correspondence between ABC and the three-phase leads, and the correspondence between LN and the two ends of the variable frequency power supply are not limited to those shown in the figure, and can be any one-to-one correspondence. L also represents the live wire, and N represents the neutral wire, but N is not grounded but suspended. In addition, L1, L2, and L3 are the three-phase winding inductances of the motor; C1 is a series capacitor, and C2 is a parallel capacitor; R1, R2, and R3 are the equivalent resistances of the windings and the core, and R is the comprehensive equivalent resistance. The rated voltage of the series and parallel resonant capacitors is not less than 3000 volts, and the resonant current is not less than 50 amps.

[0051] Taking capacitors including series capacitors and parallel capacitors as an example, no matter whether the three-phase winding is connected in star or triangle, when series resonance occurs, it can be equivalent to a series circuit of resistance, inductance and series capacitor. The schematic diagram is as follows Figure 7 As shown, the vector diagram is Figure 4 As shown. When resonance occurs, its resonant frequency is:

[0052]

[0053] Its equivalent circuit diagram is as follows Fig. 9 As shown, the vector diagram is Fig.10 shown.

[0054] The present invention also provides an AC motor dehumidification method implemented by the above-mentioned device, comprising the steps of: obtaining the connection terminals of the motor and relevant parameters of the motor; determining the connection relationship between the motor and the capacitor based on the relevant parameters of the motor, and electrically connecting the variable frequency power supply, the capacitor and the connection terminals of the motor according to the connection relationship; obtaining the initial value of the relevant temperature of the motor; connecting the input power of the variable frequency power supply (closing the input power switch), starting the variable frequency power supply (closing the running switch), adjusting the output parameter of the variable frequency power supply to make the output parameter value the initial value, and closing the output switch of the variable frequency power supply; adjusting the voltage value of the variable frequency power supply to the starting voltage value, adjusting the output frequency of the variable frequency power supply until the output frequency meets the frequency setting condition, and then increasing the output voltage of the variable frequency power supply until the output voltage meets the voltage setting condition, and dehumidifying the motor; obtaining the temperature rise value of the relevant temperature of the motor, and judging whether the temperature rise value exceeds the set threshold; when the temperature rise value does not exceed the set threshold, continuing to dehumidify the motor until the insulation resistance of the motor meets the standard; when the temperature rise value exceeds the set threshold, stopping the dehumidification.

[0055] The motor terminals are used to connect capacitors or variable frequency power supplies. The relevant parameters of the motor include the inductance value.

[0056] The frequency setting condition can be the frequency when the resonant circuit is a pure resistive circuit, or the limiting condition can be appropriately relaxed, for example, the reference parameters can be determined according to the connection method of the capacitor (series, parallel, or series-parallel). For example, when the capacitor is a series capacitor, the frequency setting condition is that the output display current is the maximum value, and when the capacitor is a parallel capacitor, the frequency setting condition is that the output display current is the minimum value.

[0057] The voltage setting condition can be that the higher the voltage, the better, provided that U1, U2 and U3 do not exceed the allowable value. The allowable value of U1 is the rated voltage of the variable frequency power supply, the allowable value of U2 is the rated voltage of the series capacitor, and the allowable value of U3 is the rated voltage between the two phases of the motor. Generally, the voltage value is less than or equal to 100V.

[0058] The starting voltage value is a relatively low voltage value, for example, 20V.

[0059] The setting threshold of the temperature rise value can be different according to different motor models, capacities, and grades of insulation materials. For example, for Class B insulation materials, the maximum temperature rise national standard stipulates that it should not exceed 80 degrees. We generally choose a temperature rise of 20 to 50 degrees (if the ambient temperature is 20 degrees, the core and winding temperature is set to 40 to 70 degrees).

[0060] In one embodiment of the present invention, the initial value of voltage is zero, the initial value of current is zero, the initial value of active power is zero, and the initial value of frequency is 50 Hz.

[0061] In one embodiment of the present invention, the step of continuing to remove moisture from the motor until the insulation resistance of the motor meets the standard includes: disconnecting the output switch of the variable frequency power supply, measuring the insulation resistance of the motor, and when the insulation resistance value meets the standard, proceeding to the next step, otherwise, opening the output switch of the variable frequency power supply and continuing to remove moisture. Meeting the standard means reaching the specified standard.

[0062] In one embodiment of the present invention, after the step of continuing to dehumidify the motor until the insulation resistance of the motor meets the standard, the step also includes: adjusting the output parameter of the variable frequency power supply so that the output parameter value is an initial value; disconnecting the output switch of the variable frequency power supply, turning off the variable frequency power supply, and disconnecting the input power of the variable frequency power supply; removing the dehumidification device from the motor and restoring the normal wiring of the motor.

[0063] In one embodiment of the present invention, the connection relationship is parallel, series or series-parallel.

[0064] In one embodiment of the present invention, before the step of obtaining the connection terminals of the motor and the relevant parameters of the motor, the step further includes obtaining operation authority, which includes: complying with safety regulations and obtaining a work ticket.

[0065] Taking a voltage station as an example, the specific AC motor moisture removal method process is as follows:

[0066] 1. First confirm the location of the equipment, the motor has been powered off and safety measures have been taken, and the work ticket has been processed.

[0067] 2. This work must be performed by no less than two persons.

[0068] 3. Measure the three-phase symmetrical balance and insulation resistance of the motor DC resistance, and if they are lower than the allowable value, it is determined that the motor has indeed been affected by moisture.

[0069] 4. Take the star connection as an example, use any one phase of the three-phase lead of the motor winding as the input end, short-circuit the other two phases as the output end, and connect a measuring voltmeter U3 and capacitor C2 in parallel at both ends (the value of C2 is determined according to the inductance of the motor winding and the applied frequency. Make sure it is inductive).

[0070] 5. Connect a capacitor C1 in series to form a series-parallel circuit, such as Figure 5 , Figure 6 shown.

[0071] 6. Connect the series-parallel circuit to the two-phase output terminals L and N of the power supply of the tide-removing device.

[0072] 7. Use infrared thermometers, temperature sensors and other means to detect the initial values ​​of the motor's core temperature, winding temperature, casing temperature, ambient temperature, humidity, etc.

[0073] 8. Turn on the power input switch of the detidal device, start the device, check that the output voltage, current, and active power are zero and the frequency is 50 Hz.

[0074] 9. Close the output switch of the tide-removing device.

[0075] 10. According to the motors with different capacities and voltage levels, gradually adjust the frequency at low voltage to find the best resonant frequency. Then gradually increase the voltage, closely check that the voltages of U2 and U3 do not exceed the allowable values, and the output current I and voltage U1 of the variable frequency power supply device do not exceed the rated values.

[0076] 11. Check the temperature (temperature rise) of the motor's core, winding or casing at any time and ensure that it does not exceed the allowable value.

[0077] 12. Periodically shut down the power supply to measure the recovery of the motor's insulation resistance and determine the dehumidification effect.

[0078] 13. After achieving the expected moisture-removing effect, adjust the frequency of the moisture-removing device to 50 Hz, and reduce the output voltage and current to zero.

[0079] 14. Disconnect the output switch of the detidal device, stop the operation of the detidal device, and disconnect the input power switch of the detidal device.

[0080] 15. Remove the motor's moisture-proof test wiring and restore the motor's normal wiring.

[0081] 16. Complete the work ticket termination procedures and restore the normal operation of the motor.

[0082] The present invention is applicable to a moisture-removing device for an AC motor. A resonant circuit is formed by a variable frequency power supply, a capacitor and a motor. The hysteresis and eddy current losses generated by the resonant circuit in the iron core of the motor are used to heat the iron core, thereby achieving the purpose of moisture removal. The AC motor moisture-removing method of the present invention is used to remove moisture from the motor, so that the iron core as a whole is heated evenly, the moisture removal speed is fast, the efficiency is high, and the effect is good. At the same time, the capacity of the variable frequency power supply is small and the weight is light. The efficiency is high and the moisture removal effect is good. Therefore, the present invention effectively overcomes some practical problems in the prior art and has a high utilization value and use significance.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A dehumidification device suitable for an AC motor, characterized in that: include: A variable frequency power supply, whose voltage waveform is a sine wave, whose voltage and frequency are adjustable, and on which an output display is provided, the output display is used to display output parameters; A capacitor, electrically connected to the variable frequency power supply and to the motor; The variable frequency power supply, the capacitor and the motor form a resonant circuit, and the resonant circuit is used to heat the iron core of the motor to achieve moisture removal; the capacitor includes a series capacitor and a parallel capacitor, the series capacitor is connected in series with the motor, and the parallel capacitor is connected in parallel with the motor; the motor is a three-phase AC motor, and the winding connection method of the three-phase AC motor is a star connection method, the first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead and the third phase lead of the motor are respectively electrically connected to the second end of the variable frequency power supply; the first end of the parallel capacitor is electrically connected to the first phase lead of the motor, and the second end of the parallel capacitor is electrically connected to the second phase lead and the third phase lead of the motor respectively; the variable frequency power supply is provided with a stop indicator light and a live working indicator light, wherein the stop indicator light is green and the live working indicator light is red.

2. The dehumidification device for AC motor according to claim 1, characterized in that: The motor is a three-phase AC motor, and the winding connection method of the three-phase AC motor is a triangle connection method. The first end of the series capacitor is electrically connected to the first end of the variable frequency power supply, the second end of the series capacitor is electrically connected to the first phase lead of the motor, and the second phase lead of the motor is electrically connected to the second end of the variable frequency power supply; the first end of the shunt capacitor is electrically connected to the first phase lead of the motor, and the second end of the shunt capacitor is electrically connected to the second phase lead of the motor.

3. A method for driving moisture with an AC motor using the device described in any one of claims 1-2, characterized in that: Includes steps: Get the motor's wiring terminals and related parameters; Determine the connection relationship between the motor and the capacitor based on the relevant parameters of the motor, and electrically connect the variable frequency power supply, the capacitor and the connection terminals of the motor according to the connection relationship; Obtaining an initial value of the relevant temperature of the motor; Connecting the input power of the variable frequency power supply, starting the variable frequency power supply, adjusting the output parameter of the variable frequency power supply so that the output parameter value is an initial value, and closing the output switch of the variable frequency power supply; The voltage value of the variable frequency power supply is adjusted to a starting voltage value, the output frequency of the variable frequency power supply is adjusted until the output frequency meets the frequency setting condition, and the output voltage of the variable frequency power supply is increased until the output voltage meets the voltage setting condition, and the motor is dehumidified; Obtaining a temperature rise value of the motor-related temperature, and determining whether the temperature rise value exceeds a set threshold; When the temperature rise value meets the set threshold, the motor continues to be dehumidified until the insulation resistance of the motor meets the standard.

4. The method for dehumidifying an AC motor according to claim 3, characterized in that: The connection relationship is parallel, series or series-parallel.

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