CN112305419A - Air-cooled motor loss separation device and loss separation method thereof - Google Patents

Air-cooled motor loss separation device and loss separation method thereof Download PDF

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CN112305419A
CN112305419A CN202011127256.0A CN202011127256A CN112305419A CN 112305419 A CN112305419 A CN 112305419A CN 202011127256 A CN202011127256 A CN 202011127256A CN 112305419 A CN112305419 A CN 112305419A
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loss
motor
air
stator
wind
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高莲莲
才智强
梁艳萍
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Harbin University of Science and Technology
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Harbin University of Science and Technology
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/34—Testing dynamo-electric machines
    • G01R31/343—Testing dynamo-electric machines in operation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R21/00—Arrangements for measuring electric power or power factor

Abstract

The invention provides a loss separation device and a loss separation method of an air-cooled motor, which comprise a wind speed detector and a wind temperature detector arranged in a motor ventilation channel, a laser and an acoustic wave sensor respectively arranged at the inner side and the outer side of a stator slot wedge, a current detector and a voltage regulator which are connected with a phase winding of a stator, and an analysis device and a display arranged on a motor shell, wherein the wind speed detector, the wind temperature detector, the laser, the acoustic wave sensor, the current detector, the voltage regulator and the display are all connected with the analysis device. The device can measure all losses of the air-cooled motor through the separating device, and separate all losses according to a loss separation method, so that the accuracy of loss measurement is improved, the loss measurement period is shortened, and objective basis can be provided for the design of a cooling system of the air-cooled motor.

Description

Air-cooled motor loss separation device and loss separation method thereof
Technical Field
The invention relates to the technical field of air-cooled motors, in particular to a loss separation device and a loss separation method for an air-cooled motor.
Background
With the vigorous development of the motor industry and the pursuit of high efficiency and high precision by people, the more accurate the measurement method of each loss of the motor is required to be in the industry, the better the measurement method is. The accurate separation of each item loss of motor can provide theoretical foundation for the derivation of each item loss formula of motor, also can provide objective foundation for cooling system's design simultaneously, and then improves the too high problem of motor temperature rise.
The method has the limitation that only a water-cooled motor can be measured, and the thermocouple is directly attached to an iron core or a shell and belongs to heat conduction, so that the conduction speed is high, and the thermocouple is used for measuring the temperature of a cooling water inlet and a cooling water outlet and then carrying out loss separation. However, the air-cooled motor cannot be used for measurement, because the heat conduction of the wind to the thermocouple depends on the heat convection, the convection speed is relatively slow, so that the transient change of the actual temperature cannot be reflected, namely the wind may become very hot in the transient process, but the thermocouple needs to be reflected in a short time, and a delay value exists, so that a separating device specially used for the loss of the air-cooled motor is absent in the prior art.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides an air-cooled motor loss separation device and a loss separation method thereof, and solves the problem that a special separation device for air-cooled motor loss is lacked in the prior art.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
the utility model provides an air-cooled motor loss separation device, it is including locating the wind speed detector and the wind temperature detector in the motor ventilation ditch, locate laser instrument and the acoustic wave sensor of stator slot wedge inside and outside respectively, all with a looks winding of stator current detector and voltage regulator be connected and locate analytical equipment and the display on the motor casing, wind speed detector, wind temperature detector, laser instrument, acoustic wave sensor, current detector, voltage regulator and display all are connected with analytical equipment.
Furthermore, the number of the air temperature detectors is two, and the two air temperature detectors are respectively arranged at the air inlet and the air outlet of the motor ventilating duct.
Further, the current detector and the voltage regulator are respectively connected in series and in parallel with the end of the stator winding.
Further, the wind speed detector and the wind temperature detector are connected with the inner wall of the motor ventilation channel through silicon rubber.
A loss separation method for an air-cooled motor specifically comprises the following steps:
the method specifically comprises the following steps:
s1, collecting the wind speed v at the air outlet of the motor ventilation ditch and the wind temperature T at the air inlet and the air outlet of the motor ventilation ditch1Wind temperature T2；
S2, according to the wind speed v and the wind temperature T1Wind temperature T2And obtaining the total loss P of the motor by adopting a total loss formula of the motor:
P＝csvρairΔT
wherein c is the specific heat of air, and Δ T ═ T2-T1S is the air outlet area of the motor ventilation channel, rhoairIs the density of air;
s3, collecting vibration sound wave data of the surface of the motor spindle, and calculating the friction coefficient C of the motor spindle according to the vibration sound wave datar；
S4, calculating the wind friction loss P of the motor spindle by adopting a wind friction loss formulaair；
S5, collecting stator current I of the statoraAccording to stator current IaCalculating the stator copper loss P by using a stator copper loss calculation formulaCu；
S6, collecting stator voltage data, and calculating the iron core loss P under any working conditionFe：
Figure BDA0002734020560000021
Wherein, PImin、PairminAnd PCuIminThe total loss, the wind friction loss and the stator copper loss of the motor corresponding to the minimum value of no-load current, U is the stator voltage of the motor under any working condition, and U is the stator voltage of the motor under any working condition0minThe stator voltage at the minimum value of no-load current;
s7, calculating the additional loss P under any working conditions：
Ps＝P-PCu-PFe-Pair。
Further, the core loss PFeThe construction method comprises the following steps:
constructing a motor total loss formula when the no-load current is the minimum value:
PImin＝PFeImin+PairImin+PCuImin
constructing a corresponding iron core loss calculation model at the minimum value of the no-load current:
Figure BDA0002734020560000031
obtaining an iron core loss formula under any working condition according to a motor total loss formula and an iron core loss calculation model when the no-load current is the minimum value:
Figure BDA0002734020560000032
further, the stator copper loss calculation formula is as follows:
Figure BDA0002734020560000033
wherein k isaIs the number of stator winding phases, RaIs a stator one-phase resistance.
Further, the formula of the wind friction loss is as follows:
Pair＝CrCfρπω3r4l
wherein, CfThe coefficient of air friction is rho, the air density is rho, the rotor angular frequency is omega, the radius of the motor rotor is r, and the axial length of the motor spindle is l.
Further, in step S, according to the stator current IaBuilding a curve I of the motor at no-load0F (u), then according to curve I0F (U) to obtain PImin、Pairmin、PCuImin、U0minAnd I0min. The resistance of the stator winding is constant by adjusting the stator endVoltage data of the section and stator current corresponding to the voltage are obtained as I0Curve f (u).
Further, the method also comprises adding additional loss PsIron core loss, wind friction loss PairStator copper loss PCuAnd the total loss P of the motor is sent to the display to be displayed.
The invention has the beneficial effects that:
the wind speed and the wind temperature of the ventilation duct of the air-cooled motor, the friction coefficient of a main shaft of the motor, the stator current and the stator voltage are measured in real time through the wind speed detector, the wind temperature detector, the laser, the sound wave sensor, the current detector and the voltage regulator, delay errors of detected data are avoided, and the measurement precision of various losses is greatly improved. The separation device and the loss separation method can be used for performing loss separation on the air-cooled motor in real time, avoid the problem that engineering personnel calculate large errors of losses of the air-cooled motor, can accurately analyze the losses of the air-cooled motor, and provide accurate objective basis for reasonable design of a motor cooling system.
Drawings
FIG. 1 is a schematic cross-sectional view of an air-cooled motor cooperating with a loss separation apparatus for an air-cooled motor.
Fig. 2 is a partial schematic view of a loss separating device of an air-cooled motor in a stator slot wedge.
Fig. 3 is an axial schematic view of a loss separation device of an air-cooled motor.
Fig. 4 is a partial schematic view of an air-cooled motor loss separation device in a motor ventilation duct.
Wherein, 1, a wind speed detector; 2. a wind temperature detector; 3. a motor ventilation channel; 4. an analysis device; 5. a display; 6. a motor housing; 7. a data wire outlet; 8. a first data line; 9. a laser; 10. a stator slot wedge; 11. a motor spindle; 12. a laser beam; 13. an acoustic wave sensor; 14. a second data line; 15. a current detector; 16. a voltage regulator.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in fig. 1 to 4, the present solution provides an air-cooled motor loss separation device, which includes an air speed detector 1 and an air temperature detector 2 disposed in a motor ventilation duct 3, a laser 9 and an acoustic wave sensor 13 respectively disposed inside and outside a stator slot wedge 10, a current detector 15 and a voltage regulator 16 both connected to a phase winding of a stator, and an analysis device 4 and a display 5 disposed on a motor housing 6, wherein the air speed detector 1, the air temperature detector 2, the laser 9, the acoustic wave sensor 13, the current detector 15, the voltage regulator 16 and the display 5 are all connected to the analysis device 4.
Specifically, the number of the wind temperature detectors 2 is two, and the two wind temperature detectors 2 are respectively arranged at the air inlet and the air outlet of the motor ventilation duct 3, so as to obtain the wind temperatures at the air inlet and the air outlet of the motor ventilation duct 3. The current detector 15 and the voltage regulator 16 are respectively connected with the end part of the stator winding in series and in parallel, and the voltage regulator 16 can regulate the terminal voltage of a phase winding of the stator of the motor in real time to obtain a drawing I0Stator voltage data of f (u). The wind speed detector 1 and the wind temperature detector 2 are connected with the inner wall of the motor ventilation ditch 3 through silicon rubber. The silicon rubber is an adhesive and belongs to direct bonding, the silicon rubber has obvious high-temperature stability, and the wind speed detector 1 and the wind temperature detector 2 are bonded in the motor ventilation duct 3, so that the silicon rubber is stable, cannot be easily lost, and is favorable for occasions where the motor rotates at high speed.
When the vibration acoustic wave sensor is used, the laser 9 emits laser beams 12 to the surface of the motor spindle 11 to form surface vibration acoustic waves, and vibration acoustic wave data are generated after the surface vibration acoustic waves are measured by the acoustic wave sensor 13. The sound wave sensor 13 is connected with the analysis device 4 through a second data line 14, and the motor housing 6 is provided with a data line leading-out port 7 through which the second data line 14 passes, so that the vibration sound wave data is transmitted to the analysis device 4 through the second data line 14. The analysis device 4 is connected with the display 5 through a first data line 8, and transmits data such as total loss of the motor, wind friction loss, stator copper loss, iron core loss and additional loss to the display 5 through the first data line 8, and the display 5 displays the data. The analyzing device 4 may employ a PLC.
A loss separation method for an air-cooled motor specifically comprises the following steps:
the method specifically comprises the following steps:
s1, collecting the wind speed v at the air outlet of the motor ventilation ditch 3 and the wind temperature T at the air inlet and the air outlet of the motor ventilation ditch 31Wind temperature T2；
S2, according to the wind speed v and the wind temperature T1Wind temperature T2And obtaining the total loss P of the motor by adopting a total loss formula of the motor:
P＝csvρairΔT
wherein c is the specific heat of air, and Δ T ═ T2-T1S is the air outlet area of the motor ventilation ditch 3, rhoairIs the density of air;
s3, collecting vibration sound wave data of the surface of the motor spindle 11, and calculating the friction coefficient C of the motor spindle 11 according to the vibration sound wave datar；
S4, calculating the wind friction loss P of the motor spindle 11 by adopting a wind friction loss formulaair；
S5, collecting stator current I of the statoraAccording to stator current IaCalculating the stator copper loss P by using a stator copper loss calculation formulaCu；
S6, collecting stator voltage data, and calculating the iron core loss P under any working conditionFe：
Figure BDA0002734020560000061
Wherein, PImin、PairminAnd PCuIminThe total loss, the wind friction loss and the stator copper loss of the motor corresponding to the minimum value of no-load current, U is the stator voltage of the motor under any working condition,U0minthe stator voltage at the minimum value of no-load current;
s7, calculating the additional loss P under any working conditions：
Ps＝P-PCu-PFe-Pair。
Further, the core loss PFeThe construction method comprises the following steps:
constructing a motor total loss formula when the no-load current is the minimum value:
PImin＝PFeImin+PairImin+PCuImin
constructing a corresponding iron core loss calculation model at the minimum value of the no-load current:
Figure BDA0002734020560000071
obtaining an iron core loss formula under any working condition according to a motor total loss formula and an iron core loss calculation model when the no-load current is the minimum value:
Figure BDA0002734020560000072
further, the stator copper loss calculation formula is as follows:
Figure BDA0002734020560000073
wherein k isaIs the number of stator winding phases, RaIs a stator one-phase resistance.
Further, the formula of the wind friction loss is as follows:
Pair＝CrCfρπω3r4l
wherein, CfIs the air friction coefficient, ρ is the air density, ω is the rotor angular frequency, r is the motor rotor radius, and l is the axial length of the motor spindle 11.
Further, in step S6, according to the determinationSub-current IaBuilding a curve I of the motor at no-load0F (u), then according to curve I0F (U) to obtain PImin、Pairmin、PCuImin、U0minAnd I0min。
Further, the method also comprises adding additional loss PsIron core loss, wind friction loss PairStator copper loss PCuAnd the total motor loss P are sent to the display 5 for display.

Claims (10)

1. The utility model provides an air-cooled motor loss separator, its characterized in that, including wind speed detector (1) and wind temperature detector (2) of locating in motor ventilation ditch (3), locate laser instrument (9) and acoustic wave sensor (13) of stator slot wedge (10) inside and outside respectively, current detector (15) and voltage regulator (16) all are connected with a phase winding of stator and locate analytical equipment (4) and display (5) on motor casing (6), wind speed detector (1), wind temperature detector (2), laser instrument (9), acoustic wave sensor (13), current detector (15), voltage regulator (16) and display (5) all are connected with analytical equipment (4).
2. The air-cooled motor loss separation device according to claim 1, wherein the number of the air temperature detectors (2) is two, and the two air temperature detectors (2) are respectively arranged at an air inlet and an air outlet of the motor ventilating duct (3).
3. The air-cooled motor loss separation device according to claim 1, wherein the current detector (15) is connected in series with the end of the stator winding, and the voltage regulator (16) is connected in parallel with the end of the stator winding.
4. The air-cooled motor loss separation device is characterized in that the wind speed detector (1) and the wind temperature detector (2) are connected with the inner wall of the motor ventilating duct (3) through silicon rubber.
5. The loss separation method of the loss separation device of the air-cooled motor according to any one of claims 1 to 4, comprising the following steps:
s1, collecting the wind speed v at the air outlet of the motor ventilation ditch (3) and the wind temperature T at the air inlet and the air outlet of the motor ventilation ditch (3)1Wind temperature T2；
S2, according to the wind speed v and the wind temperature T1Wind temperature T2And obtaining the total loss P of the motor by adopting a total loss formula of the motor:
P＝csvρairΔT
wherein c is the specific heat of air, and Δ T ═ T2-T1S is the air outlet area of the motor ventilation ditch (3), rhoairIs the density of air;
s3, collecting vibration sound wave data of the surface of the motor spindle (11), and calculating the friction coefficient C of the motor spindle (11) according to the vibration sound wave datar；
S4, calculating the wind friction loss P of the motor spindle (11) by adopting a wind friction loss formulaair；
S5, collecting stator current I of the statoraAccording to stator current IaCalculating the stator copper loss P by using a stator copper loss calculation formulaCu；
S6, collecting stator voltage data, and calculating the iron core loss P under any working conditionFe：
Figure FDA0002734020550000021
Wherein, PImin、PairminAnd PCuIminThe total loss, the wind friction loss and the stator copper loss of the motor corresponding to the minimum value of no-load current, U is the stator voltage of the motor under any working condition, and U is the stator voltage of the motor under any working condition0minThe stator voltage at the minimum value of no-load current;
s7, calculating the additional loss P under any working conditions：
Ps＝P-PCu-PFe-Pair。
6. The method of claim 5Loss separation method, characterized in that the core loss PFeThe construction method comprises the following steps:
constructing a motor total loss formula when the no-load current is the minimum value:
PImin＝PFeImin+PairImin+PCuImin
constructing a corresponding iron core loss calculation model at the minimum value of the no-load current:
Figure FDA0002734020550000022
obtaining an iron core loss formula under any working condition according to a motor total loss formula and an iron core loss calculation model when the no-load current is the minimum value:
Figure FDA0002734020550000023
7. the loss separation method of claim 5, wherein the stator copper loss calculation formula is:
Figure FDA0002734020550000031
wherein k isaIs the number of stator winding phases, RaIs a stator one-phase resistance.
8. The loss separation method of claim 5, wherein the wind friction loss formula is:
Pair＝CrCfρπω3r4l
wherein, CfThe air friction coefficient is rho, the air density is rho, the rotor angular frequency is omega, the motor rotor radius is r, and the axial length of the motor spindle (11) is l.
9. The loss separation method according to claim 5, wherein in step S6, the stator current I is determined according toaBuilding a curve I of the motor at no-load0F (u), then according to curve I0F (U) to obtain PImin、Pairmin、PCuImin、U0minAnd I0min。
10. The loss separation method of claim 5, further comprising coupling the additional loss PsIron core loss, wind friction loss PairStator copper loss PCuAnd the total loss P of the motor are sent to a display (5) for displaying.
CN202011127256.0A 2020-10-20 2020-10-20 Air-cooled motor loss separation device and loss separation method thereof Pending CN112305419A (en)

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