CN102969956A - Device and method for measuring electromotive force of fan motor - Google Patents

Abstract

The invention relates to a device and a method for measuring electromotive force of a fan motor, which utilizes a wind tunnel device capable of changing air quantity to generate fluid, and then the fluid guides the fan motor to be measured to rotate; the technology can enable the fan motor to be tested to quickly obtain stable rotating speed, does not need compressed air, achieves the measurement of the induced electromotive force constants under the rated rotating speed and a plurality of different rotating speeds, obtains the key characteristic parameters of the fan motor to be tested, and can qualitatively observe the degree of the eddy current effect of the motor.

Description

Device and method for measuring electromotive force of fan motor

This case is a divisional application. The application number of its parent case is 201010145709.2, and the application date is April 9, 2010. The applicant is: Industrial Technology Research Institute, and the name of the invention is: device and method for measuring electromotive force of fan motor.

technical field

The invention relates to a device and method for measuring the electromotive force of a fan motor, especially a principle of using a small wind tunnel device; using the flow field to drive the fan blades to rotate in a non-contact manner, and is characterized in that it can provide a controllable stable fluid Speed, drive the fan blades to rotate to a single or multiple different stable speeds, no need to provide additional power supply and controller to drive the motor to rotate, and can quickly and stably obtain the motor speed; when the fan motor to be tested is driven to a predetermined speed, Cooperate with the oscilloscope to measure the induced voltage and operating frequency of the motor.

Background technique

When it is desired to test a fan motor to be tested, an auxiliary motor is usually used to drive the fan motor to be tested, and the auxiliary motor and the fan motor to be tested are pivotally connected through a coupler to make the fan motor to be tested run to the rated value. The rotation speed of the fan motor to be tested can be determined by measuring the waveform and amplitude of the induced electromotive force constant of the fan motor to be tested by an electrical measuring device (see the following formula (1)), and then the quality of the fan motor to be tested can be judged.

E _emf ＝ke·ω(1)

in,

E _emf : Motor induced electromotive force

ke: motor induced electromotive force constant

ω: motor speed

There are some technical problems in this test method. For example, the fan motor to be tested must be coupled with the auxiliary motor at the driving end, and the two must have a good centering structure or method to a certain extent, otherwise the bearing of the fan motor to be tested will be damaged. In addition, the purchased servo motors (auxiliary motors) and controllers are expensive. In addition, among the current international motor characteristic testing manufacturers, few manufacturers have developed this level of testing equipment for motor induced electromotive force constants for single micro motors. At present, the general industry widely uses the method of testing the electromotive force constant of the fan motor, which is to blow the compressed air directly to the fan blade through the air gun (see Figure 1), or provide power through a controller to make the fan blade rotate, and then use infrared rays or The synchronous stroboscope detects its running speed, or obtains the running frequency with a waveform processor to measure the induced electromotive force constant of the fan motor.

According to the Steinmetz empirical formula (see the following formula (2)):

P _e ＝K _e f ² B _m ² t ² (2)

in,

P _e : motor eddy current loss

K _e : The eddy current constant of the iron core material

f: motor operating frequency

B _m : Magnetic flux density in the core

t: Thickness of core material

It can be understood that there is a linear proportional relationship between the magnitude of the motor eddy current and the square of the rotational speed. In other words, as the motor speed increases, the motor eddy current loss will increase rapidly. Therefore, how to qualitatively observe the degree of the motor eddy current effect is more important . In order to qualitatively understand the eddy current loss induced by the motor stator silicon steel sheet, it is necessary to measure the curve of the induced electromotive force against different speeds to observe the eddy current between the developed motor and the calibrated motor (using the motor performance as the benchmark) The difference in the degree of loss is used as the basis for improving the efficiency of the motor.

The induced electromotive force constant in the magnetic circuit parameters of a permanent magnet motor is closely related to the performance, output, and operable operating speed of the motor itself. The methods disclosed and taught in the prior art for measuring the induced electromotive force constant are as follows:

The first measurement method is a "measurement method of motor induced electromotive force constant" disclosed in U.S. Patent No. US6998814. It uses a driver to drive the motor in a single-phase rotation mode. The rotational speed of the motor is output by a speed encoder. The electromotive force is the AC peak value after integrating the relationship between the phase voltage and the predetermined rotational speed.

However, there are some problems and shortcomings in the above method and technology. The fan motor disclosed in the scope of this patent is a three-phase permanent magnet motor with sensing. The position of the rotor is sensed by the Hall element, and the rotational speed is output by a speed encoder. , to drive the motor through the controller, which cannot be implemented on single-phase fan motors or three-phase permanent magnet non-sensing fan motors.

The second measurement method is an "inductive signal detection device for brushless DC motor" disclosed in Taiwan Patent No. 202265, which uses a signal coil for signal detection, and drives the motor through a controller. The circuit includes a Hall element to detect the angular position of the motor rotation and drive the motor to rotate, and the signal is detected at the output end of the signal coil.

However, there are certain problems and shortcomings in the above method and technology. The fan motor disclosed in the scope of the patent is a sensor motor. Although the signal is not output through the Hall element, a signal coil must be wound. This method is not suitable for On-line inspection during mass production.

The third measurement method is the method of testing the induced electromotive force constant of the fan motor widely used in the industry, that is, as shown in Figure 1, a relay 71 provides the necessary power, and simultaneously connects an air gun 72 and a rotational speed measuring device 74, and the compressed air The air gun 72 directly blows air to the fan blade 731 of a fan motor 73 to be tested, drives the fan blade 731 to rotate, and then uses a rotational speed measuring device 74 (consisting of an infrared ray or a synchronous strobe) to detect its operating speed value. The running speed value is transmitted to a computer 75 or a waveform processor through a computer connection port 751 to obtain the running frequency, so as to achieve the purpose of measuring the electrical characteristics of the fan motor.

However, there are certain problems and shortcomings in the above-mentioned method and technology. The air gun 72 directly blows air to the fan blade 731, and its rotational speed is not easy to control, and only one area of the fan blade 731 will be subjected to gas pressure, which will cause an error in the measured value of the induced electromotive force. It is also easy to cause the shaft connected to the fan blade 731 to be skewed and damaged, which will also affect the measured value of Kemax. Furthermore, this method cannot make the fan motor 73 under test run at different stable speeds.

Since the induced electromotive force constant affects the torque output and performance of the motor itself, how to propose a method that can run the fan motor to be tested to the desired speed in the undriven state, and can maintain this speed, At the same time, different stable operating speeds can be realized to obtain the above-mentioned induced electromotive force constants at different rotating speeds. In this way, the post-processing work can be performed without additional software to solve the measurement problem caused by the unstable motor speed, and further the degree of the eddy current effect can be obtained. Above, no effective solution can be proposed by reviewing the prior art. Therefore, the present invention proposes a device and method for measuring the induced electromotive force constant of a motor, which can solve the above-mentioned deficiencies in the prior art.

Contents of the invention

Based on solving the deficiencies of the above-mentioned prior art, the present invention is a device and method framework for measuring the electromotive force of a fan motor. The main purpose is to provide a principle of using a small wind tunnel device; use the flow field to drive the fan blade in a non-contact manner Rotation, which is characterized in that it can provide a controllable and stable fluid velocity, drive the fan blades to rotate to a single or multiple different stable speeds, and do not need to provide additional power and controllers to drive the motor to rotate, and can quickly and stably obtain the motor speed; After the fan motor to be tested is driven to a predetermined rotational speed, measure the induced voltage and operating frequency of the motor with an oscilloscope.

To achieve the above purpose, the present invention is a method for measuring the electromotive force of a fan motor, which includes:

Installing a fan motor to be tested and an auxiliary fan motor to a wind tunnel device;

Whether the detection software of the fan motor to be tested has been started and operated normally by a computer, if yes, the next step is executed; if no, the execution ends;

Set the parameters of the fan motor speed to be tested and the default value of the induced electromotive force of the detection software of the computer, and the detection parameters of the induced electromotive force of the fan motor to be tested include a phase voltage and a frequency value;

Start the auxiliary fan motor to rotate the fan motor under test;

Detect the speed value of the fan motor under test and send it back to the computer;

The computer judges whether the rotational speed of the fan motor to be tested conforms to the preset rotational speed of the fan motor to be tested, if yes, executes the next step; if not, executes an action of automatically adjusting the rotational speed until it meets the rotational speed of the fan motor to be tested;

The computer obtains the actual rotational speed of the fan motor to be tested, and calculates the actual value of the induced electromotive force of the fan motor to be tested;

The computer compares the actual value of the induced electromotive force of the fan motor to be tested with the aforementioned default value to determine whether the fan motor to be tested is a qualified product. the action recorded; and

The computer judges whether the work of detecting the fan motor to be tested is finished, if not, re-executes all the aforementioned steps; if so, directly finishes the work.

In the above-mentioned method for measuring the electromotive force of the fan motor, the detection parameters of the induced electromotive force of the fan motor to be tested include a phase voltage and a frequency value.

In the above method for measuring the electromotive force of the fan motor, the speed of the fan to be tested is adjusted by adjusting the speed of the auxiliary fan motor.

To achieve the above purpose, the present invention is a device for measuring the electromotive force of a fan motor, which includes:

A wind tunnel device has a tube body, one end of the tube body is provided with a first cover, and the first cover is connected with an auxiliary fan motor, and the other end of the tube body is provided with a second cover, the second cover A fixing seat is arranged on the cover, and the fixing seat is used for connecting and fixing a fan motor to be tested;

A rotational speed measuring device, which is electrically connected to the fan motor to be tested, and measures and outputs its induced electromotive force value;

A computer is electrically connected to the fan motor to be tested through a computer connection port and receives the induced electromotive force value output by the rotational speed measuring device. The computer has a detection software, which can set the rotational speed of the fan motor to be measured and The parameter of the default value of the induced electromotive force is used to determine whether the speed of the fan motor to be tested conforms to the preset speed of the fan motor to be tested and compare the actual value of the induced electromotive force of the fan motor to be tested with the default value to determine whether the fan motor to be tested is Qualified products, and implement the activation of warning devices and recording actions; and

A warning device is connected with the computer, and accepts its instruction to decide to open the warning device.

The above-mentioned device for measuring the electromotive force of the fan motor, the rotating speed measuring device refers to an oscilloscope or a tachometer.

In the above-mentioned device for measuring the electromotive force of the fan motor, the value of the induced electromotive force output by the rotational speed measuring device can be recorded manually.

In the above-mentioned device for measuring electromotive force of a fan motor, the type of the fan motor to be tested is a single-phase permanent magnet motor or a three-phase permanent magnet motor.

In the above-mentioned device for measuring electromotive force of a fan motor, the power of the auxiliary fan motor is greater than the power of the fan motor to be tested.

In the above device for measuring the electromotive force of the fan motor, the connection and fixing method between the fixing seat and the fan motor to be tested is screwing or bonding.

In the above-mentioned device for measuring electromotive force of a fan motor, the auxiliary fan motor is composed of a frequency-variable axial flow fan.

The above-mentioned device for measuring the electromotive force of the fan motor, the device for measuring the electromotive force of the fan motor also includes a computer, which is electrically connected to the fan motor to be tested through a computer connection port and receives the value of the induced electromotive force output by the speed measuring device. The computer has a detection software, which can be used to set the parameters of the fan motor speed under test and the default value of induced electromotive force, judge whether the speed of the fan motor under test meets the preset speed of the fan motor under test The actual value is compared with the default value to judge whether the fan motor under test is a qualified product.

The above-mentioned device for measuring the electromotive force of the fan motor, the computer also includes a plurality of application software and a storage unit, and the application software includes a setting unit, a sampling unit, an automatic control unit, a comparison unit and a judgment unit .

In the above-mentioned device for measuring electromotive force of a fan motor, the storage unit refers to a hard disk or a memory.

The above-mentioned device for measuring the electromotive force of the fan motor, the device for measuring the electromotive force of the fan motor also includes a warning device connected to the computer, and accepts its instruction to determine to open the warning device.

In the device for measuring the electromotive force of the fan motor, the warning device is a light emitting diode or a buzzer.

In order to further describe the present invention more deeply, the following diagrams, descriptions of figure numbers and detailed description of the invention are used.

Description of drawings

FIG. 1 is a schematic diagram of the structure of an existing fan motor electromotive force measuring device;

2A is a schematic diagram of the structure of the first embodiment of the device for measuring the electromotive force of the fan motor of the present invention;

2B is a schematic diagram of the structure of the second embodiment of the device for measuring the electromotive force of the fan motor of the present invention;

3A and 3B are flowcharts of the method for measuring the electromotive force of the fan motor of the present invention;

4A is a three-dimensional exploded schematic diagram of the wind tunnel device, the fan motor to be tested and the auxiliary fan motor of the present invention;

Fig. 4B is a schematic cross-sectional structure diagram of the wind tunnel device of the present invention, the fan motor to be tested and the auxiliary fan motor;

Fig. 5 is a functional block schematic diagram of the internal software and hardware of the computer of the present invention.

[Description of main component symbols]

10～Start

11～Install a fan motor to be tested and an auxiliary fan motor to a wind tunnel device

12～Use a computer to detect whether the detection software of the fan motor to be tested has been started and is operating normally

13～Set the parameters of the default value of the fan motor speed to be tested and the induced electromotive force of the computer's detection software

14～Start the auxiliary fan motor to rotate the fan motor under test

15～Detect the speed value of the fan motor to be tested and send it back to the computer

16~The computer judges whether the speed of the fan motor to be tested conforms to the preset speed of the fan motor to be tested

17～Automatic speed adjustment action

18～The computer obtains the actual speed of the fan motor to be tested, and calculates the actual value of the induced electromotive force of the fan motor to be tested

19～The computer compares the actual value of the induced electromotive force of the fan motor to be tested with the aforementioned default value to determine whether the fan motor to be tested is a good product

20～Start the warning device

21～record

22～The computer judges whether the work of detecting the fan motor to be tested is over

23～End

3. 75 ~ computer

31. 751～computer connection port

32～storage unit

33～setting unit

34～sampling unit

35～automatic control unit

36～comparison unit

37～judgment unit

4～Wind tunnel device

41～Auxiliary fan motor

42, 73 ~ fan motor to be tested

43～Tube body

431～cavity

44～first cover

45～second cover

451～fixed seat

5. 74～speed measuring device

6～Warning device

61～LED

62～Buzzer

71～relay

72～air gun

731～fan blade

Detailed ways

The detailed structure of the present invention and its connection relationship are described in conjunction with the following drawings, so as to further describe the purpose, scheme and effect of the present invention.

Please refer to Figure 2A, which is a schematic diagram of the first specific implementation of the fan motor electromotive force measuring device of the present invention. This embodiment does not need to be connected to a computer, and can be directly interpreted manually. The principle of the hole device 4; use the auxiliary fan motor 41 to drive the flow field to drive the fan blade of the fan motor 42 to be tested in a non-contact manner, which can provide a controllable different stable fluid velocity, and drive the fan blade to rotate to a single or multiple different The stable speed does not need to provide additional power supply and controller to drive the motor to rotate, and the motor speed can be obtained quickly and stably; when the fan motor to be tested is driven to a predetermined speed, cooperate with a speed measuring device 5 to measure the induced voltage of the motor , operating frequency, and then manually interpret to determine whether the two values are standard, as a basis for judging whether the fan motor 42 to be tested is a qualified product.

Table 1. The comparison table of the fan motor induced electromotive force test method and device proposed by the present invention compared with the prior art

For the second specific embodiment, please refer to Fig. 2B, Fig. 4A and B, which are schematic diagrams of the structure of the fan motor electromotive force measuring device of the present invention and the structural schematic diagrams of the wind tunnel device of the present invention, the fan motor to be tested and the auxiliary fan motor, which include: A wind tunnel device 4 has a pipe body 43, the cavity in the pipe body forms an air passage, and one end of the pipe body is provided with a first cover, and the first cover 44 is connected with an auxiliary fan motor 41, the auxiliary fan The motor 41 is composed of a frequency-variable axial flow fan, and the other end of the tube body 43 is provided with a second cover 45. The first cover 44 and the second cover 45 are fixed by a plurality of fixing components 46. Fixed, the second cover 45 is provided with a fixing seat 451, the fixing seat 451 is used for connecting and fixing a fan motor 42 to be tested, and the fixing method for connecting and fixing the fixing seat 451 and the fan motor 42 to be tested is screwing or bonding. The type of the fan motor 42 to be tested is a single-phase permanent magnet motor or a three-phase permanent magnet motor, and the power of the auxiliary fan motor 41 is greater than the power of the fan motor 42 to be tested; The motor 42 is electrically connected, and measures and outputs its induced electromotive force value. The rotational speed measuring device 5 refers to an oscilloscope or a tachometer; and receive the induced electromotive force value output by the rotational speed measuring device 5, the computer 3 has a detection software, which can set the parameters of the rotational speed of the fan motor 42 to be tested and the default value of the induced electromotive force, and judge the fan motor 42 to be tested Whether the rotation speed conforms to the preset rotation speed of the fan motor 42 to be tested and compare the actual value of the induced electromotive force of the fan motor 42 to be tested with the default value to judge whether the fan motor 42 to be tested is a qualified product, and execute the activation warning device 6 and Record action; a warning device 6 is connected with the computer 3, and accepts its instruction to decide to open the warning device 6. The warning device 6 is a light-emitting diode (LED) 61 or a buzzer 62. By lighting or warning The sound is used to remind the tester of the existence of the defective fan motor 42 to be tested.

Please refer to shown in Fig. 5, it is the functional block schematic diagram of software and hardware inside the computer of the present invention, more comprises a plurality of application software and a storage unit 32 in this computer 3, and this storage unit 32 refers to a hard disk or internal memory, these The application software includes a setting unit 33 , a sampling unit 34 , an automatic control unit 35 , a comparing unit 36 and a judging unit 37 .

Please refer to Figures 3A and 3B, which are flow charts of the method for measuring the electromotive force of the fan motor of the present invention, which include:

10～start;

11～Install a fan motor to be tested and an auxiliary fan motor to a wind tunnel device;

12～Using a computer to detect whether the detection software of the fan motor to be tested has been started and is operating normally, if yes, execute the next step; if no, execute and end;

13～Set the parameters of the fan motor speed to be tested and the default value of the induced electromotive force in the detection software of the computer;

14～Start the auxiliary fan motor to rotate the fan motor to be tested;

15 ~ Detect the speed value of the fan motor to be tested, and send it back to the computer;

16. The computer judges whether the speed of the fan motor to be tested conforms to the preset speed of the fan motor to be tested. If yes, proceed to the next step; , and the speed adjustment of the fan to be tested is achieved by adjusting the speed of the auxiliary fan motor;

18～The computer obtains the actual rotational speed of the fan motor to be tested, and calculates the actual value of the induced electromotive force of the fan motor to be tested;

19～The computer compares the actual value of the induced electromotive force of the fan motor to be tested with the aforementioned default value to judge whether the fan motor to be tested is a good product, if yes, execute 21~record action; if not, execute 20~start Actions to be recorded after a warning device; and

22～The computer judges whether the work of detecting the fan motor to be tested is finished, if not, re-execute all the aforementioned steps; if yes, directly proceed to 23～finish the work.

The method and device for measuring the induced electromotive force constant of a micro motor disclosed by the present invention mainly use a small wind tunnel device, the device is provided with a cavity; one end of the cavity is provided with a fluid generating device and a fixing seat for generating the fluid device, The flow generated by the fluid generating device can be controlled, and the other end of the cavity is provided with a fixing seat of the fan motor to be tested, and the fan motor to be tested is installed on the fixing seat. The device is equipped with an automatic adjustment system for the speed of the fan motor to be tested. The system is equipped with an oscilloscope and a computer. The phase voltage and operating frequency of the fan motor are measured by the oscilloscope, and the waveform of the induced voltage of the phase is recorded by the oscilloscope. Through the computer software program Calculate and compare the difference between the set speed and the actual speed, and adjust the fluid generating device. When the speed of the fan motor to be tested reaches the set speed, start measuring the phase induction voltage and operating frequency of the fan motor, and record the value with an oscilloscope. Phase induced voltage and frequency, according to the phase induced voltage and operating frequency, through the existing relationship between induced phase voltage and rotational speed, obtain the motor induced electromotive force constant, and compare it with the design value to identify whether it is qualified or not.

In summary, the structural features and various embodiments of the present invention have been disclosed in detail, and it can be fully demonstrated that the present invention is highly progressive in terms of purpose and effect, has great industrial utilization value, and is currently the Unprecedented application on the market.

Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art can make various corresponding modifications according to the present invention without departing from the spirit and essence of the present invention. Changes and modifications, but these corresponding changes and modifications should fall within the scope of protection of the appended claims of the present invention.

Claims (12)

1. A fan motor electromotive force measuring device comprises:

the wind tunnel device is provided with a pipe body, a cavity in the pipe body forms an air flow channel, one end of the pipe body is provided with a first sealing cover, the first sealing cover is connected with an auxiliary fan motor, the other end of the pipe body is provided with a second sealing cover, the second sealing cover is provided with a fixed seat, and the fixed seat is used for connecting and fixing a fan motor to be measured; and

and the rotating speed measuring device is electrically connected with the fan motor to be measured and is used for measuring and outputting the induced electromotive force value.

2. The apparatus for measuring electromotive force of a fan motor according to claim 1, wherein the rotational speed measuring means is an oscilloscope or a tachometer.

3. The apparatus as claimed in claim 1, wherein the value of the induced electromotive force outputted from the rotational speed measuring device is manually recorded.

4. The apparatus as claimed in claim 1, wherein the fan motor to be tested is a single-phase permanent magnet motor or a three-phase permanent magnet motor.

5. The apparatus of claim 1, wherein the auxiliary fan motor has a power greater than the fan motor to be tested.

6. The apparatus for measuring electromotive force of a fan motor according to claim 1, wherein the fixing base is fixed to the fan motor to be measured by screwing or adhesion.

7. The apparatus as claimed in claim 1, wherein the auxiliary fan motor is a variable frequency axial fan.

8. The apparatus as claimed in claim 1, further comprising a computer electrically connected to the fan motor to be tested through a computer port and receiving the induced electromotive force value outputted from the rotational speed measuring device, wherein the computer has a detection software for setting the rotational speed of the fan motor to be tested and the parameter of the default value of the induced electromotive force, determining whether the rotational speed of the fan motor to be tested matches a predetermined rotational speed of the fan motor to be tested, and comparing the actual value of the induced electromotive force of the fan motor to be tested with the default value to determine whether the fan motor to be tested is qualified.

9. The apparatus as claimed in claim 8, wherein the computer further comprises a plurality of application software and a storage unit, the application software comprises a setting unit, a sampling unit, an automatic control unit, a comparison unit and a determination unit.

10. The apparatus of claim 9, wherein the storage unit is a hard disk or a memory.

11. The apparatus as claimed in claim 8, wherein the apparatus further comprises a warning device connected to the computer and receiving the command to turn on the warning device.

12. The apparatus for measuring electromotive force of a fan motor according to claim 11, wherein the warning device is a light emitting diode or a buzzer.

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