CN111505530B - Non-contact coil fault detection system based on electromagnetic induction and detection method thereof - Google Patents
Non-contact coil fault detection system based on electromagnetic induction and detection method thereof Download PDFInfo
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- CN111505530B CN111505530B CN202010276269.8A CN202010276269A CN111505530B CN 111505530 B CN111505530 B CN 111505530B CN 202010276269 A CN202010276269 A CN 202010276269A CN 111505530 B CN111505530 B CN 111505530B
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- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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Abstract
The invention relates to a non-contact coil fault detection system based on electromagnetic induction and a detection method thereof, wherein the system comprises a signal excitation module, a signal induction module and a signal detection module, and the detection method comprises the following steps: determining the sampling resistance power without electromagnetic induction and the sampling resistance power with electromagnetic induction; detecting the on-off condition of an induction coil, namely a detected coil; and detecting the short circuit condition of the induction coil, namely the coil to be detected. The detection method does not need to disconnect the tested module, only needs to externally sense an excitation module, and therefore a detection mode which cannot damage a tested object is more convenient, and the requirements on detection workers are reduced in the traditional detection mode; the induction test is quicker, the tested coil does not need to be disassembled, the detection flow is shortened, and the time for detecting the fault is shortened.
Description
Technical Field
The invention belongs to the technical field of nondestructive testing of coils in devices, and particularly relates to a non-contact coil fault detection system based on electromagnetic induction and a detection method thereof.
Background
With the continuous development of electromagnetic induction technology, the related technology and products have been widely applied and produced in military and civil fields. In the military aspect, weapons and equipment such as radars, coil guns and the like all utilize the electromagnetic induction principle, and coil structures are used; in the civil aspect, the related technologies and products relate to the aspects of life and production, electromagnetic induction type wireless chargers, generators, electromagnetic induction toothbrushes, electromagnetic induction shavers, induction cookers and the like; in the industrial aspect, the related products are rather countless. The coil structures are contained in the products, and the normal use of the products can be ensured only by ensuring that the coil structures are not broken or short-circuited. At present, to the fault detection of coil, can only unpack the inside universal meter that carries out the contact detection with the product apart, but this kind of detection not only can waste a large amount of time, can lose huge financial resources and materials moreover, and the most important can't confirm the short circuit point when the coil short circuit. At the present stage, no non-contact fault detection scheme specially aiming at the coil inside the device can integrate the on-off and the short circuit of the detection coil.
Disclosure of Invention
In view of this, the present invention provides a non-contact coil fault detection system based on electromagnetic induction, which detects an internal coil of a device using the principle of electromagnetic induction, improves detection efficiency, simplifies detection steps more effectively, and avoids damage to an object to be detected.
In order to achieve the purpose, the technical scheme is as follows:
referring to fig. 1-4, a system for detecting a fault of a non-contact coil based on electromagnetic induction includes:
the signal excitation module comprises an excitation coil and a signal source, the excitation coil is electrically connected with the signal source, the signal source provides proper alternating current signals, the excitation coil generates excitation current under the power supply of the signal source, the excitation current is changed current, so that the magnetic field generated by the excitation coil around changes according to the electromagnetic induction law, a changed magnetic field is formed, and the signal excitation module starts to work;
the signal induction module comprises an induction coil, the induction coil and the excitation coil are arranged in parallel and correspondingly, under the work of the signal excitation module, the induction coil does not generate induced electromotive force, the circuit is not closed, the induction coil is open-circuited, and the induction coil generates induced electromotive force, so that the circuit is a closed loop and the induction coil is not open-circuited;
the signal detection module is connected with the signal excitation module in series and comprises a sampling resistor and an ammeter which are electrically connected in sequence, so that the on-off condition of the induction coil is judged according to the actual power and the expected power of the sampling resistor, whether the signal is short-circuited or not can be judged by detecting the signal and comparing the signal with an expected result, and a short-circuit point can be further judged.
As a further improvement of the present invention, the signal sensing module further comprises a circuit load connected in series with the sensing coil.
As a further improvement of the invention, the signal detection module also comprises a power size identifier and an indicator light which are connected with a sampling resistor and an ammeter in series, the actual power and the expected power of the sampling resistor are differentiated, and the difference is transmitted into the power size identifier and compared with the expected power of the induction module.
A non-contact coil fault detection method based on electromagnetic induction comprises the following steps:
s1, determining sampling resistance power P without electromagnetic induction1And the power P of the sampling resistor where electromagnetic induction occurs2；
S2, detecting the on-off condition of the induction coil, namely the detected coil
The induction coil can generate induced electromotive force only under the condition of being closed, so that whether the induction coil is open-circuited or not can be judged according to the detection of the existence of the induced electromotive force in the induction coil, the fact that the induction coil is closed loop or not indicates that the signal induction module is not closed loop, and the fact that the induction coil is open is indicated by the existence of the induced electromotive force; according to this principle, if P1＝P2If no induction signal is generated, the open circuit detection of the induction coil is finished, if P is detected1〉P2Then there is a sensing signalIf the coil is not disconnected, the next step is needed to detect whether the coil has a short circuit phenomenon;
s3, detecting the short circuit condition of the induction coil, namely the detected coil
With regard to the detection of whether a short circuit or not, a comparison P is required1And P2The difference DeltaP between the desired power of the induction coil
Size of (1), if
The coil has no short circuit, the detection is finished, if so
The coil is short-circuited, and the number of short-circuit turns or a short-circuit point needs to be further determined; similarly, the number of short circuit turns is also determined by
Is calculated from the difference of (a).
The invention has the beneficial effects that:
firstly, materials are not lost in a non-contact mode, the impedance or power of two ends of a coil to be detected is roughly measured through a universal meter in the traditional scheme, an induction module is required to be disassembled, namely the module to be detected is obtained, the detection method does not need to disconnect the module to be detected, only one excitation module is required to be externally induced, and therefore a detected object cannot be damaged, on the other hand, if the impedance of the coil to be detected is reduced under the condition of short circuit, once a power supply is turned on for detection, the universal meter is likely to be damaged;
secondly, the detection mode is more convenient, the requirement on detection workers is reduced, and compared with the traditional detection mode, the detection mode only needs the workers to enable the signal detection module to be close to the signal induction module and then judge according to the indicator light;
and thirdly, the induction test is quicker, the tested coil does not need to be disassembled, the detection flow is shortened, and the time is shortened for detecting the fault.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a system configuration diagram of the present invention;
FIG. 2 is a schematic diagram of the operation of the present invention;
FIG. 3 is a schematic equivalent of the present invention;
fig. 4 is a flow chart of the present invention.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Non-contact coil fault detection system based on electromagnetic induction includes:
the signal excitation module 10 comprises an excitation coil 11 and a signal source 12, the excitation coil 11 is electrically connected with the signal source 12, the signal source 12 provides a proper alternating current signal, the excitation coil 11 generates an excitation current under the power supply of the signal source 12, the excitation current is a variable current, so that a magnetic field generated by the excitation coil 11 around changes according to the law of electromagnetic induction, a variable magnetic field is formed, and the signal excitation module 10 starts to work;
the signal induction module 20 comprises an induction coil 21, the induction coil 21 and the excitation coil 11 are arranged in parallel and correspondingly, and the signal induction module further comprises a circuit load 22 connected with the induction coil 21 in series, under the work of the signal excitation module 10, the induction coil 21 does not generate induced electromotive force, the circuit is not closed, the induction coil 21 is open-circuited, and when the induction coil 21 generates induced electromotive force, the circuit is a closed loop, and the induction coil 21 is not open-circuited; that is, the signal sensing module 20 is actually the coil module to be detected, and in combination with the actual circuit, it is equivalent to an induction coil 21 and a load resistor. When the energized excitation module is close to the detected coil module, the induction coil 21 generates a phenomenon that induced electromotive force is generated under the influence of a changing magnetic field generated by the excitation coil 11, which indicates that the induction coil 21 module is a closed loop; a second phenomenon: no induced electromotive force is generated, indicating that the module of the induction coil 21 is not a closed loop. This module is primarily to provide comparison and reference for the subsequent signal detection module 30;
the signal detection module 30 is connected in series with the signal excitation module 10, the signal detection module 30 comprises a sampling resistor 31 and an ammeter 32 which are electrically connected in sequence, in addition, the signal detection module 30 further comprises a power size identifier 33 and an indicator lamp 34 which are connected in series with the sampling resistor 31 and the ammeter 32, and the indicator lamp 34 mainly has the function of displaying the on-off condition of the coil to be detected, so that the on-off condition of the induction coil 21 is judged according to the actual power and the expected power of the sampling resistor 31, and whether the signal is short-circuited or not can be judged by detecting the size of the signal and comparing the size of the signal with an expected result, and the short-circuit point can be further judged; when the exciting coil 11 and the electromagnetic coil generate mutual inductance due to electromagnetic induction, the impedance of the whole circuit can be equivalent to the impedance of the exciting module and another equivalent impedance which are connected in series; when the exciting coil 11 and the electromagnetic coil do not generate mutual inductance, the impedance of the whole circuit is the impedance of the exciting module, and the voltage on the component is changed due to the change of the impedance, so that the power on the component is changed. Therefore, the function of the signal detection module 30 is mainly to determine the on-off condition and the short-circuit condition of the induction coil 21 module, i.e. the coil module to be detected, by detecting the voltage of the sampling resistor 31 and then calculating the power thereof, and the power comparator is used to compare the actual power with the expected power: the actual power of the sampling resistor 31 is compared with the expected power to detect the on-off of the coil, and the actual power of the induction module is compared with the expected power to judge the short circuit condition of the coil.
A non-contact coil fault detection method based on electromagnetic induction comprises the following steps:
s1, determining power P of sampling resistor 31 without electromagnetic induction1And the power P of the sampling resistor 31 where electromagnetic induction occurs2；
S2, detecting the on-off condition of the induction coil 21, namely the detected coil
Only when the induction coil 21 is closed, the induction electromotive force can be generated, so that whether the induction coil 21 is open-circuited or not can be judged according to the detection of the existence of the induction electromotive force in the induction coil 21, the existence of the induction electromotive force indicates that the signal induction module 20 is a closed loop, the induction coil 21 is not opened, and the noneductive electromotive force indicates that the signal induction module 20 is not a closed loop and the induction coil 21 is opened; according to this principle, if P1＝P2If no induction signal is generated, the open circuit detection of the induction coil 21 is finished, and if P is detected1〉P2If so, generating an induction signal, and detecting whether the coil is short-circuited or not in the next step if the coil is not disconnected;
s3, detecting the short circuit condition of the induction coil 21, namely the coil to be detected
With regard to the detection of whether a short circuit or not, a comparison P is required1And P2The difference DeltaP between the current and the desired power of the induction coil 21
Size of (1), if
The coil has no short circuit, the detection is finished, if so
The coil is short-circuited, and the number of short-circuit turns or a short-circuit point needs to be further determined; similarly, the number of short circuit turns is also determined by
Is calculated from the difference of (a).
The principle of the electromagnetic induction based contactless coil fault detection scheme is further explained with reference to an example and embodiments as shown in fig. 2:
as can be seen from the figure:
(R1+jwL1)I1-jwMI2＝U (1)
-jwMI1+(jwL2+R2)I2＝0 (2)
from (2) can be obtained:
substituting (3) into (1) to obtain:
let Z1＝jwL1+R1，Z2＝jwL2+R2Then the equivalent impedance at the input (looking to the right when the power supply is disconnected) is:
from the above formula, it can be seen that: when the tested coil is disconnected and no induction signal is generated, the impedance of the input end is only the impedance of the sampling resistor 31 and the excitation coil 11; when the coil to be tested is not broken and the induction coil 21 is generated, the impedance of the input end can be equivalent to
I.e. an impedance of, in addition to the impedance of the sampling resistor 31 and the excitation coil 11, one
I.e. the impedance of the induction coil 21 and the load resistance.
This equivalent diagram is shown in fig. 3. Open circuit of coil, phase when induction module is not closed loopWhen the switch is closed, the impedance is
Short-circuiting the resistance of (1); the coil has no open circuit, when the induction module is a closed loop, the switch is opened, Z1And Z3Are connected in series.
For the calculation of the power of the circuit elements, according to P ═ I2R, when no electromagnetic induction occurs, the element power is:
when electromagnetic induction occurs, the element power is as follows:
combine (6) and (7), and
if the value is larger than zero, the power P 'of the sampling resistor 31 after the electromagnetic induction occurs'1<P1Therefore, the power of the sampling resistor 31 can be tested to determine the on/off of the induction coil 21.
Setting the current of the measured circuit as I, and if the measured coil is completely short-circuited, Z3＝R2At a power of Pmin＝I2R2(ii) a If the tested coil is not short-circuited, the test coil is not short-circuited
With a power of
And because of
If P ismin＜ΔP＜PmaxThe coil short circuit can be known; if Δ P ═ PmaxIt can be known that the coil is not short-circuited and is detectedThe module works normally.
Besides, P 'can be measured'1Then, the voltage of the exciting coil 11 is derived from the equation, and P 'is calculated'3Then calculates the values of (6) and (7)
And further calculating the number of short circuit turns.
In the formula:
I1、I2respectively representing the excitation module current and the induction module current;
R1、R2representing the resistance of the excitation module sampling resistor 31 and the resistance of the sensing module load resistor;
L1、L2representing the inductances of the exciting coil 11 and the induction coil 21, respectively;
m represents the mutual inductance between the two coils;
u represents an alternating voltage signal provided by a power supply;
P3、P′3respectively representing the power of the exciting coil 11 before and after electromagnetic induction;
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (4)
1. Non-contact coil fault detection system based on electromagnetic induction, its characterized in that includes:
the signal excitation module comprises an excitation coil and a signal source, the excitation coil is electrically connected with the signal source, the signal source provides proper alternating current signals, the excitation coil generates excitation current under the power supply of the signal source, the excitation current is changed current, so that the magnetic field generated by the excitation coil around changes according to the electromagnetic induction law, a changed magnetic field is formed, and the signal excitation module starts to work;
the signal induction module comprises an induction coil, the induction coil and the excitation coil are arranged in parallel and correspondingly, under the work of the signal excitation module, the induction coil does not generate induced electromotive force, the circuit is not closed, the induction coil is open-circuited, and the induction coil generates induced electromotive force, so that the circuit is a closed loop and the induction coil is not open-circuited;
the signal detection module is connected with the signal excitation module in series and comprises a sampling resistor and an ammeter which are electrically connected in sequence, so that the on-off condition of the induction coil is judged according to the actual power and the expected power of the sampling resistor, if the induction coil is in open circuit, the difference between the actual power and the expected power of the sampling resistor can be calculated, and then the difference is compared with the expected power of the induction module to judge whether the induction coil is in short circuit or not and judge a short circuit point.
2. The electromagnetic induction based contactless coil fault detection system of claim 1 wherein the signal sensing module further comprises a circuit load in series with the induction coil.
3. The electromagnetic induction based non-contact coil fault detection system of claim 1, wherein the signal detection module further comprises a power level identifier and an indicator light connected in series with a sampling resistor and a current meter, wherein the actual power and the expected power of the sampling resistor are differentiated and the difference is transmitted to the power level identifier and compared with the expected power of the induction module.
4. A non-contact coil fault detection method based on electromagnetic induction is characterized by comprising the following steps:
s1, determining sampling resistance power P without electromagnetic induction1And the power P of the sampling resistor where electromagnetic induction occurs2；
S2, detecting the on-off condition of the induction coil, namely the detected coil
The induction coil can generate induced electromotive force only under the condition of being closed, so that whether the induction coil is open-circuited or not can be judged according to the detection of the existence of the induced electromotive force in the induction coil, the fact that the induction coil is closed loop or not indicates that the signal induction module is not closed loop, and the fact that the induction coil is open is indicated by the existence of the induced electromotive force; according to this principle, if P1＝P2If no induction signal is generated, the open circuit detection of the induction coil is finished, if P is detected1〉P2If so, generating an induction signal, and detecting whether the coil is short-circuited or not in the next step if the coil is not disconnected;
s3, detecting the short circuit condition of the induction coil, namely the detected coil
With regard to the detection of whether a short circuit or not, a comparison P is required1And P2The difference DeltaP between the desired power of the induction coil
Size of (1), if
The coil has no short circuit, the detection is finished, if so
The coil is short-circuited, and the number of short-circuit turns or a short-circuit point needs to be further determined; similarly, the number of short circuit turns is also determined by
Is calculated from the difference of (a).
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| CN117970192A (en) * | 2024-04-02 | 2024-05-03 | 清华四川能源互联网研究院 | Method and system for detecting closed loop coil |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11275715A (en) * | 1998-03-19 | 1999-10-08 | Railway Technical Res Inst | Device for detecting abnormality in levitation guide coil |
| CN103728533A (en) * | 2014-01-16 | 2014-04-16 | 北京航空航天大学 | High-power non-contact charging system main circuit fault detection device |
| CN203849392U (en) * | 2013-08-23 | 2014-09-24 | 深圳市贝斯达医疗器械有限公司 | Magnetic resonance superconducting coil fault testing tool |
| CN104251947A (en) * | 2014-08-26 | 2014-12-31 | 龙口中宇机械有限公司 | Electromagnetic coil fault diagnosis device |
| CN107110907A (en) * | 2015-01-15 | 2017-08-29 | Lg伊诺特有限公司 | Abnormal equipment for determining wireless power transmission coil |
-
2020
- 2020-04-09 CN CN202010276269.8A patent/CN111505530B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11275715A (en) * | 1998-03-19 | 1999-10-08 | Railway Technical Res Inst | Device for detecting abnormality in levitation guide coil |
| CN203849392U (en) * | 2013-08-23 | 2014-09-24 | 深圳市贝斯达医疗器械有限公司 | Magnetic resonance superconducting coil fault testing tool |
| CN103728533A (en) * | 2014-01-16 | 2014-04-16 | 北京航空航天大学 | High-power non-contact charging system main circuit fault detection device |
| CN104251947A (en) * | 2014-08-26 | 2014-12-31 | 龙口中宇机械有限公司 | Electromagnetic coil fault diagnosis device |
| CN107110907A (en) * | 2015-01-15 | 2017-08-29 | Lg伊诺特有限公司 | Abnormal equipment for determining wireless power transmission coil |
Non-Patent Citations (2)
| Title |
|---|
| A New Detection Coil Capable of Performing Online Diagnosis of Excitation Winding Short-Circuits in Steam-Turbine Generators;W. Yucai,et al.;《IEEE Transactions on Energy Conversion》;20180331;第33卷(第1期);106-115 * |
| 利用漏磁辐射的非接触式开关电源稳定性探测方法;王鹰等;《电子科技大学学报》;20120531;第41卷(第3期);388-391 * |
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