CN111208344A - Common mode current detection device and method - Google Patents
Common mode current detection device and method Download PDFInfo
- Publication number
- CN111208344A CN111208344A CN201811390750.9A CN201811390750A CN111208344A CN 111208344 A CN111208344 A CN 111208344A CN 201811390750 A CN201811390750 A CN 201811390750A CN 111208344 A CN111208344 A CN 111208344A
- Authority
- CN
- China
- Prior art keywords
- value
- mode current
- voltage
- common mode
- current detection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2506—Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values ; Details concerning sampling, digitizing or waveform capturing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention discloses a common mode current detection device and a method, wherein the device comprises: the detection module is sleeved outside the positive and negative wire harnesses of the detected cable and used for sensing the common-mode current of the detected cable and generating sensing voltage; and the voltage sampling module is used for sampling the induction voltage to obtain an induction voltage value. The device can effectively detect the existing common-mode current by collecting the induction voltage, thereby realizing the rapid detection and analysis of the common-mode current, and having small volume and low cost.
Description
Technical Field
The present invention relates to the field of common mode current detection technologies, and in particular, to a common mode current detection apparatus and a common mode current detection method.
Background
With the development of science and technology, highly intelligent power electronic devices are rapidly developed, and the devices can better serve human beings and simultaneously generate larger electromagnetic interference problems. Any power electronic equipment can generate an electromagnetic field, and excessive electromagnetic emission can cause the problems of abnormal operation and even damage of other power electronic equipment. The common-mode current generated by the power electronic equipment during operation is an important way for transmitting electromagnetic interference, and accurate measurement is required before symptomatic medicine administration.
The existing equipment for testing the common-mode current is mainly based on a contact voltage probe and a sampling separation loop, and the common-mode current in the circuit is sampled and separated and then is detected by a high-precision analysis system. However, such devices are generally expensive, typically in the hundreds of thousands to millions of RMB's, and they are also bulky.
Disclosure of Invention
The present invention is directed to solving at least one of the problems in the art to some extent. Therefore, an object of the present invention is to provide a common mode current detection device, which can effectively detect the existing common mode current by collecting the induced voltage, so as to realize the fast detection and analysis of the common mode current, and the device has a small volume and a low cost.
Another objective of the present invention is to provide a common mode current detection method.
In order to achieve the above object, an embodiment of an aspect of the present invention provides a common mode current detection apparatus, including: the detection module is sleeved on the outer sides of the positive and negative wire harnesses of the cable to be detected and used for sensing the common-mode current of the cable to be detected and generating sensing voltage; and the voltage sampling module is used for sampling the induction voltage to obtain an induction voltage value.
According to the common mode current detection device provided by the embodiment of the invention, the detection module is sleeved on the outer sides of the positive and negative wire harnesses of the detected cable and used for sensing the common mode current of the detected cable and generating the sensing voltage, and the voltage sampling module is used for sampling the sensing voltage to obtain the sensing voltage value. Therefore, the device can effectively detect the existing common-mode current by collecting the induced voltage, so that the common-mode current can be quickly detected and analyzed, and the device is small in size and low in cost.
In addition, the common mode current detection device according to the above embodiment of the present invention may further have the following additional technical features:
according to one embodiment of the invention, the detection module comprises: the annular acquisition magnetic core is sleeved outside the positive and negative wire harnesses of the tested cable; and the induction coil is wound on the annular acquisition magnetic core, and two ends of the induction coil are respectively connected with the voltage sampling module.
According to an embodiment of the present invention, the common mode current detection apparatus further includes: and the frequency sampling module is used for sampling the number of the positive half cycles and the negative half cycles of the induction voltage to obtain a half cycle count value.
According to one embodiment of the invention, the frequency sampling module comprises: the first light-emitting diode is respectively connected with two ends of the detection module and used for emitting a first optical signal when the induction voltage is in a positive half period; a second light emitting diode connected in anti-parallel with the first light emitting diode for emitting a second light signal when the induced voltage is in a negative half period; the phototriode is used for conducting when the first optical signal or the second optical signal is received; and the counting module is respectively connected with two ends of the phototriode and is used for counting the conduction times of the phototriode to obtain the half-period counting value.
According to an embodiment of the present invention, the common mode current detection apparatus further includes: and the controller is used for analyzing the induction voltage value and the half-cycle counting value, and if the induction voltage value is not constant or the half-cycle counting value is greater than 1, calculating a frequency value of the induction voltage according to the half-cycle counting value, and/or calculating a maximum value of an instantaneous value of the induction voltage according to the induction voltage value, and/or calculating a minimum value of the instantaneous value of the induction voltage, and/or calculating a sum of an absolute value of the maximum value and an absolute value of the minimum value.
According to an embodiment of the invention, the controller is further configured to: and if the induction voltage value is constant and the half-cycle count value is equal to 1, judging that the detected cable is in electric leakage, and outputting an electric leakage alarm signal.
According to an embodiment of the present invention, the common mode current detection apparatus further includes: and the display module is used for displaying the frequency value, and/or the maximum value, and/or the minimum value, and/or the sum value, and/or the leakage alarm signal.
According to an embodiment of the present invention, the common mode current detection apparatus further includes: the overvoltage protection module is connected with the detection module in parallel and used for short-circuiting when the induction voltage is larger than a preset voltage threshold value and breaking when the induction voltage is equal to or smaller than the preset voltage threshold value.
According to one embodiment of the invention, the overvoltage protection module is a clamping diode.
According to an embodiment of the present invention, the apparatus for detecting a common mode current further includes: and the capacitor is respectively connected with the detection module and the voltage sampling module and is used for buffering and storing the induction voltage.
In order to achieve the above object, another embodiment of the present invention provides a common mode current detection method, including the following steps: the detection module sleeved outside the positive and negative electrode wire harnesses of the tested cable senses the common-mode current of the tested cable to generate a sensing voltage; and the voltage sampling module samples the induction voltage to obtain an induction voltage value.
According to the common-mode current detection method provided by the embodiment of the invention, the common-mode current of the cable to be detected is induced to generate the induced voltage, and then the induced voltage is sampled to obtain the induced voltage value, so that the existing common-mode current can be effectively detected, and the rapid detection and analysis of the common-mode current can be realized.
In addition, the common mode current method according to the above embodiment of the present invention may further have the following additional technical features:
according to an embodiment of the present invention, the common mode current detection method further includes: and the frequency sampling module samples the number of the positive half period and the negative half period of the induction voltage to obtain a half period count value.
According to an embodiment of the present invention, the common mode current detection method further includes: the controller analyzes the induction voltage value and/or the half-cycle count value; if the induction voltage value is not constant or the half-cycle count value is greater than 1, the controller calculates a frequency value of the induction voltage according to the half-cycle count value, and/or calculates a maximum value of an instantaneous value of the induction voltage according to the induction voltage value, and/or calculates a minimum value of the instantaneous value of the induction voltage, and/or calculates a sum of an absolute value of the maximum value and an absolute value of the minimum value; and if the induction voltage value is constant and the half-cycle count value is equal to 1, judging that the detected cable is in electric leakage by the controller, and outputting an electric leakage alarm signal.
According to an embodiment of the present invention, the common mode current detection method further includes: the display module displays the frequency value, and/or the maximum value, and/or the minimum value, and/or the sum value, and/or the leakage alarm signal.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which,
fig. 1 is a schematic structural diagram of a common mode current detection device according to an embodiment of the present invention;
FIG. 2 is a test schematic of a common mode current sensing device according to one embodiment of the invention;
fig. 3 is a schematic structural diagram of a common mode current detection device according to another embodiment of the present invention;
fig. 4 is an external view of a common mode current detection device according to an embodiment of the present invention;
fig. 5 is an operation schematic diagram of a common mode current detection apparatus according to a specific example of the present invention;
fig. 6 is a flow chart of a common mode current detection method according to one embodiment of the invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
A common mode current detection apparatus proposed according to an embodiment of the present invention is described below with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a common mode current detection device according to an embodiment of the present invention. As shown in fig. 1, the apparatus includes: a detection module 10 and a voltage sampling module 20.
The detection module 10 is sleeved outside the positive and negative electrode wire harnesses of the cable to be detected, and is used for sensing the common mode current of the cable to be detected and generating an induced voltage. The voltage sampling module 20 is configured to sample the induced voltage to obtain an induced voltage value.
Further, in an embodiment of the present invention, as shown in fig. 1, the detection module 10 may include: a toroidal pick-up core 101 and an induction coil 102.
As shown in fig. 2, the annular collecting magnetic core 101 is sleeved outside the positive and negative electrode wire harnesses of the tested cable; as shown in fig. 1, an induction coil 102 is wound around an annular collecting core 101, and two ends of the induction coil 102 are respectively connected to the voltage sampling modules 20. The annular collecting magnetic core 101 can be designed to be an open type or a closed type according to actual needs. When the common mode current exists in the tested cable, the common mode current can be sensed by the sensing coil 102 because the common mode current on the positive wire harness and the negative wire harness has the same direction and the magnetic field is doubled.
Specifically, as shown in fig. 3, when the common-mode current of the cable needs to be detected, the above-mentioned device is placed on the cable to be detected, and it is required that the positive and negative electrode wire harnesses of the same loop must be simultaneously sleeved in the annular collecting magnetic core 101. When there is common mode current, detection device 10 can respond to the common mode current of being surveyed the cable to produce induced voltage, voltage adopts module 20 can detect out the voltage of response, thereby obtains the induced voltage value, simultaneously, can generate the induced voltage waveform according to induced voltage, through carrying out the analysis to the induced voltage waveform, help further understanding the common mode current of being surveyed the cable, realize the swift detection and the analysis of common mode current. And, detection module 10 comprises annular collection magnetic core 101 and induction coil 102, and voltage sampling module 20 can comprise divider resistance, voltage follower, AD chip, and common mode current detection device comprises comparatively basic components and parts promptly, low cost, and each components and parts volume is less.
Therefore, the common-mode current detection device provided by the embodiment of the invention can effectively detect the existing common-mode current by collecting the induced voltage, so that the common-mode current can be quickly detected and analyzed, and the device has the advantages of small volume, low cost and convenience in application and popularization.
According to an embodiment of the present invention, as shown in fig. 3, the common mode current detection apparatus may further include: and the frequency sampling module 30, the frequency sampling module 30 is configured to sample the number of the positive half cycles and the negative half cycles of the induced voltage to obtain a half cycle count value.
Further, as shown in fig. 3, the frequency sampling module 30 may include: the counting module comprises a first light emitting diode LED1, a second light emitting diode LED2, a phototransistor VT1 and a counting module 301.
The first light emitting diode LED1 is respectively connected to two ends of the detection module 10, and is configured to emit a first light signal when the induced voltage is in a positive half period. The second light emitting diode LED2 is connected in anti-parallel with the first light emitting diode LED1 for emitting a second light signal when the induced voltage is in the negative half cycle. The phototransistor VT1 is configured to turn on when receiving the first optical signal or the second optical signal. The counting module 301 is respectively connected to two ends of the phototransistor VT1, and is configured to count the number of times of conduction of the phototransistor VT1, so as to obtain a half-cycle count value.
Specifically, when the common mode current exists in the tested cable, the induced voltage is transmitted to the second LED2 and the first LED 1. Because the capacity of the light emitting diode required by being lighted is very small, the light emitting diode can be lighted by a tiny induction voltage, and when the induction voltage is in a positive half period, the first light emitting diode LED1 is lighted; when the induced voltage is in the negative half-cycle, the second light emitting diode LED2 is illuminated. When the second LED2 or the first LED1 is lit, the photo transistor VT1 senses light conduction. The counting module 301 may count the conduction number of the phototransistor VT1 in the timing mode to obtain a half-period count value n. And then the common-mode current detection device can analyze the frequency value f of the induced voltage according to n, analyze whether the tested cable leaks electricity according to n, and analyze the induced voltage according to the induced voltage value.
The following describes how to analyze the frequency value f of the induced voltage according to n, and whether the tested cable leaks electricity according to n, and analyze the induced voltage according to the value u of the induced voltage.
According to an embodiment of the present invention, as shown in fig. 3, the common mode current detection apparatus may further include: a controller 40. The controller 40 may be configured to analyze the induced voltage value u and the half-cycle count value n, and if the induced voltage value u is not constant or the half-cycle count value is greater than 1, calculate a frequency value f of the induced voltage according to the half-cycle count value n, and/or calculate a maximum value u of an instantaneous value of the induced voltage according to the induced voltage value umaxAnd/or minimum value u of instantaneous value of induced voltageminAnd/or absolute value | u of the maximum valuemaxAbsolute value of | and minimum | uminSum of | up-p。
The controller 40 may also be configured to: and if the induction voltage value u is constant and the half-period count value n is equal to 1, judging that the detected cable is in leakage, outputting a leakage alarm signal and prompting a user to further detect the leakage.
Specifically, the induced voltage value refers to an effective value of the induced voltage, and the controller 40 may perform operation and processing according to the half-period count value n stored in the counting module 301 in the unit time and the induced voltage value u collected by the voltage collecting module 2. First, the controller 40 determines n and u, if n is equal to 1, that is, only one diode of the second LED2 and the first LED1 is lit once, and if the n value is not increased after a proper delay, a special process is performed: i.e. actively controlling electricityThe voltage sampling module 2 performs sampling for multiple times, the collected induction voltage value u is relatively constant, and the constant induction voltage value u refers to the fact that the induction voltage values u are the same or similar, which indicates that the current in a direct current form is detected, the cable to be detected is likely to generate electric leakage, and the controller sends an electric leakage alarm signal to remind electric leakage. And if n is greater than 1, the frequency value f of the induced voltage can be calculated according to the formula f-n/2; if the collected induced voltage value u is not constant, the maximum value u of the instantaneous value of the induced voltage can be obtained according to the collected induced voltage value umaxMinimum value u of instantaneous value of induced voltageminAbsolute value of maximum value | umaxAbsolute value of | and minimum | uminSum of | up-pWherein u ismaxU (positive maximum), uminU (negative minimum), up-p＝|umax|+|uminIf the common-mode current is not influenced, the method is convenient for users to take relevant measures.
According to an embodiment of the present invention, as shown in fig. 3, the common mode current detection apparatus may further include: a display module 50. The display module 50 is used for displaying the frequency values f, and/or the maximum values umaxAnd/or a minimum value uminAnd/or the sum value up-pAnd/or a leakage warning signal.
That is, the display module 50 may display the frequency value f and the maximum value u obtained by the controller 40maxMinimum value uminThe sum up-pThe electric leakage alarm signal is displayed, so that a user can conveniently know the condition of the tested cable, and the user can conveniently overhaul the tested cable.
In order to improve the safety and reliability of the operation of the common mode current detection device, as shown in fig. 3, according to an embodiment of the present invention, the common mode current detection device may further include: an overvoltage protection module 60 and a capacitor C. The overvoltage protection module 60 is connected in parallel with the detection module 10, and configured to short circuit when the induced voltage u is greater than the preset voltage threshold, and open circuit when the induced voltage u is equal to or less than the preset voltage threshold, where the overvoltage protection module 60 may be a clamping diode TVS. The capacitor C is respectively connected to the detection module 10 and the voltage sampling module 20, and is configured to buffer and store the induced voltage u.
Specifically, as shown in fig. 3, the preset voltage threshold is set according to the clamping range of the clamping diode TVS, and if the induced voltage u is larger than the preset voltage threshold, the clamping diode TVS enters the short-circuit mode, so that the rear-stage circuit can be protected from impact; and if the induced voltage u is equal to or less than the preset voltage threshold, the TVS is disconnected, and the rear-stage circuit works normally. The capacitor C can buffer and store the induced voltage, namely, the induced voltage is subjected to smoothing treatment, and the impact of peak voltage on the circuit is avoided. Therefore, the safety and reliability of the operation of the common mode current detection device can be improved.
It can be understood that the appearance of the common mode current detection device of the present invention can be as shown in fig. 4, wherein 70 in fig. 4 can be a human-machine operation button, which is convenient for a user to operate the common mode current detection device. Of course, the appearance of the common mode current detection device may be in other forms, and is not particularly limited.
In order to make the working principle of the common mode current detection device shown in fig. 3 in the present application more clearly understood by those skilled in the art, the following description is made with reference to the flowchart of fig. 5. Fig. 5 is a schematic diagram of an operation of a common mode current detecting apparatus according to a specific example of the present invention, as shown in fig. 5, the operation of the apparatus includes the steps of:
s101, starting a detection device.
Specifically, the positive and negative electrode wire harnesses in the same loop may be simultaneously sleeved in the annular collecting magnetic core 101, and the detection device is turned on and basically set to start detection.
S102, the clamping diode TVS determines whether the induced voltage u exceeds a preset voltage threshold. If yes, executing step S103; if not, step S104 is executed.
And S103, conducting and short-circuiting the clamping diode TVS.
S104, the clamping diode TVS is turned off, and then, step S105 is performed.
S105, when the induced voltage is transmitted to the second light emitting diode LED2 or the first light emitting diode LED1, the LED1 or the LED2 is lighted.
Specifically, when the common mode current exists in the tested cable, the induced voltage is transmitted to the second light emitting diode LED2 or the first light emitting diode LED 1. Because the capacity of the light emitting diode required by being lighted is very small, the light emitting diode can be lighted by a tiny induction voltage, and when the induction voltage is in a positive half period, the first light emitting diode LED1 is lighted; when the induced voltage is in the negative half-cycle, the second light emitting diode LED2 is illuminated.
S106, the phototransistor VT1 is turned on.
Specifically, when the second LED2 or the first LED1 is turned on, the photo transistor VT1 senses the light conduction.
And S107, the counting module works, the conduction times of the photosensitive triode VT1 are counted in the timing mode to obtain a half-period counting value n, and the voltage sampling module works to obtain an induced voltage value u.
And S108, analyzing the induced voltage value u and/or the half-cycle count value n by the controller.
S109, the controller determines whether or not n is 1 and the induced voltage value u is constant. If yes, go to step S110; if not, step S111 is performed.
And S110, the display module sends out a leakage alarm signal.
S111, the controller calculates a frequency value f of the induced voltage according to the formula f ═ n/2, and/or obtains a maximum value umax of the instantaneous value of the induced voltage, and/or a minimum value umin of the instantaneous value of the induced voltage, and/or a sum up-p of the absolute value | umax | of the maximum value and the absolute value | umin | of the minimum value, according to the value u of the induced voltage.
S112, the display module displays the frequency value f, and/or umax, and/or umin, and/or up-p.
Specifically, if n is equal to 1, that is, only one diode of the second LED2 and the first LED1 is lit once, if there is no increase in n after a proper delay, then the special process is performed: the voltage sampling module is actively controlled to sample for multiple times, if the acquired induced voltage value u is relatively constant, the fact that the current in the direct current mode is detected indicates that the cable to be detected is likely to leak electricity, and the controller sends an electricity leakage alarm signal to remind of the electricity leakage.
And if n is greater than 1, the frequency value f of the induced voltage can be calculated according to the formula f-n/2; if the collected induced voltage value u is not constant, the maximum value u of the instantaneous value of the induced voltage can be obtained according to the collected induced voltage value umaxMinimum value u of instantaneous value of induced voltageminAbsolute value of maximum value | umaxAbsolute value of | and minimum | uminSum of | up-pWherein u ismaxU (positive maximum), uminU (negative minimum), up-p＝|umax|+|uminIf the common-mode current is not influenced, the method is convenient for users to take relevant measures.
In summary, according to the common mode current detection device in the embodiment of the present invention, the detection module is sleeved outside the positive and negative electrode harnesses of the detected cable, and is configured to sense the common mode current of the detected cable and generate an induced voltage, and the voltage sampling module is configured to sample the induced voltage to obtain an induced voltage value. Therefore, the device can effectively detect the existing common-mode current by collecting the induced voltage, so that the common-mode current can be quickly detected and analyzed, and the device is small in size and low in cost. The common mode current detection device adopts simpler and more basic components to form the device, and is low in manufacturing cost; in addition, the non-contact magnetic core is adopted for detection, the tested wire harness does not need to be reconstructed and disassembled during testing, and the operation is simple and easy; besides common mode current detection, the device also has the function of direct current leakage current detection, and is wider in application range.
Based on the common mode current detection device, the invention also provides a common mode current detection method. Since the method embodiment of the present invention is based on the apparatus embodiment, details that are not disclosed in the method embodiment may refer to the apparatus embodiment, and are not described again in detail.
Fig. 6 is a flow chart of a common mode current detection method according to one embodiment of the invention. As shown in fig. 6, the method comprises the steps of:
and S1, sensing the common mode current of the cable to be detected by the detection module sleeved outside the positive and negative electrode wire harnesses of the cable to be detected to generate sensing voltage.
And S2, the voltage sampling module samples the induction voltage to obtain an induction voltage value.
Specifically, as shown in fig. 3, when the common-mode current of the cable needs to be detected, the detection device is placed on the cable to be detected, and it is required that the positive and negative electrode harnesses in the same loop must be simultaneously sleeved in the annular collecting magnetic core 101. When there is common mode current, detection device 10 can respond to the common mode current of being surveyed the cable to produce induced voltage, voltage adopts module 20 can detect out the voltage of response, thereby obtains the induced voltage value, simultaneously, can generate the induced voltage waveform according to induced voltage, through carrying out the analysis to the induced voltage waveform, help further understanding the common mode current of being surveyed the cable, realize the swift detection and the analysis of common mode current. And, detection module 10 comprises annular collection magnetic core 101 and induction coil 102, and voltage sampling module 20 can comprise divider resistance, voltage follower, AD chip, and common mode current detection device comprises comparatively basic components and parts promptly, low cost, and each components and parts volume is less.
Therefore, the common-mode current detection method provided by the embodiment of the invention can effectively detect the existing common-mode current by collecting the induced voltage, so that the common-mode current can be quickly detected and analyzed.
According to an embodiment of the present invention, the common mode current detection method may further include: the frequency sampling module samples the number of the positive half period and the negative half period of the induction voltage to obtain a half period count value.
According to an embodiment of the present invention, the common mode current detection method may further include: the controller analyzes the induction voltage value and the half-period counting value; if the value of the induced voltage is not constant or the half-cycle count value is greater than 1, the controller calculates a frequency value of the induced voltage based on the half-cycle count value, and/or calculates a maximum value of an instantaneous value of the induced voltage, and/or a minimum value of the instantaneous value of the induced voltage, and/or a sum of absolute values of the maximum value and the minimum value, based on the value of the induced voltage.
According to an embodiment of the present invention, the common mode current detection method may further include: if the induction voltage value is constant and the half-period count value is equal to 1, the controller judges that the detected cable is in leakage and outputs a leakage alarm signal.
According to an embodiment of the present invention, the common mode current detection method may further include: the display module displays the frequency value, and/or the maximum value, and/or the minimum value, and/or the sum value, and/or the electric leakage alarm signal.
In summary, according to the common mode current detection method of the embodiment of the invention, the common mode current of the cable to be detected is induced to generate the induced voltage, and then the induced voltage is sampled to obtain the induced voltage value, so that the existing common mode current can be effectively detected, and the rapid detection and analysis of the common mode current can be realized. Besides common mode current detection, the device also has the function of direct current leakage current detection, and is wider in application range.
In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (14)
1. A common mode current detection device, comprising:
the detection module is sleeved on the outer sides of the positive and negative wire harnesses of the cable to be detected and used for sensing the common-mode current of the cable to be detected and generating sensing voltage;
and the voltage sampling module is used for sampling the induction voltage to obtain an induction voltage value.
2. The common mode current detection device according to claim 1, wherein the detection module comprises:
the annular acquisition magnetic core is sleeved outside the positive and negative wire harnesses of the tested cable;
and the induction coil is wound on the annular acquisition magnetic core, and two ends of the induction coil are respectively connected with the voltage sampling module.
3. The common mode current detection device according to claim 1, further comprising:
and the frequency sampling module is used for sampling the number of the positive half cycles and the negative half cycles of the induction voltage to obtain a half cycle count value.
4. The common mode current detection device of claim 3, wherein the frequency sampling module comprises:
the first light-emitting diode is respectively connected with two ends of the detection module and used for emitting a first optical signal when the induction voltage is in a positive half period;
a second light emitting diode connected in anti-parallel with the first light emitting diode for emitting a second light signal when the induced voltage is in a negative half period;
the phototriode is used for conducting when the first optical signal or the second optical signal is received;
and the counting module is respectively connected with two ends of the phototriode and is used for counting the conduction times of the phototriode to obtain the half-period counting value.
5. The common mode current detection device according to claim 3, further comprising:
and the controller is used for analyzing the induction voltage value and the half-cycle counting value, and if the induction voltage value is not constant or the half-cycle counting value is greater than 1, calculating a frequency value of the induction voltage according to the half-cycle counting value, and/or calculating a maximum value of an instantaneous value of the induction voltage according to the induction voltage value, and/or calculating a minimum value of the instantaneous value of the induction voltage, and/or calculating a sum of an absolute value of the maximum value and an absolute value of the minimum value.
6. The common-mode current detection device of claim 4, wherein the controller is further configured to:
and if the induction voltage value is constant and the half-cycle count value is equal to 1, judging that the detected cable is in electric leakage, and outputting an electric leakage alarm signal.
7. The common mode current detection device according to claim 6, further comprising:
and the display module is used for displaying the frequency value, and/or the maximum value, and/or the minimum value, and/or the sum value, and/or the leakage alarm signal.
8. The common mode current detection device according to claim 1, further comprising:
the overvoltage protection module is connected with the detection module in parallel and used for short-circuiting when the induction voltage is larger than a preset voltage threshold value and breaking when the induction voltage is equal to or smaller than the preset voltage threshold value.
9. A common-mode current detecting device according to claim 3, characterized in that the overvoltage protection module is a clamping diode.
10. The common mode current detection device according to claim 1, further comprising:
and the capacitor is respectively connected with the detection module and the voltage sampling module and is used for buffering and storing the induction voltage.
11. A common mode current detection method is characterized by comprising the following steps:
the detection module sleeved outside the positive and negative electrode wire harnesses of the tested cable senses the common-mode current of the tested cable to generate a sensing voltage;
and the voltage sampling module samples the induction voltage to obtain an induction voltage value.
12. The common mode current detection method according to claim 11, further comprising: and the frequency sampling module samples the number of the positive half period and the negative half period of the induction voltage to obtain a half period count value.
13. The common mode current detection method according to claim 11, further comprising:
the controller analyzes the induction voltage value and the half-period counting value;
if the induced voltage value is not constant or the half-cycle count value is greater than 1, the controller calculates a frequency value of the induced voltage according to the half-cycle count value, and/or calculates a maximum value of an instantaneous value of the induced voltage, and/or calculates a minimum value of the instantaneous value of the induced voltage, and/or calculates a sum of an absolute value of the maximum value and an absolute value of the minimum value according to the induced voltage value;
and if the induction voltage value is constant and the half-cycle count value is equal to 1, the controller judges that the detected cable is leaked and outputs a leakage alarm signal.
14. The common mode current detection method according to claim 13, further comprising:
the display module displays the frequency value, and/or the maximum value, and/or the minimum value, and/or the sum value, and/or the leakage alarm signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811390750.9A CN111208344A (en) | 2018-11-21 | 2018-11-21 | Common mode current detection device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811390750.9A CN111208344A (en) | 2018-11-21 | 2018-11-21 | Common mode current detection device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111208344A true CN111208344A (en) | 2020-05-29 |
Family
ID=70785247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811390750.9A Pending CN111208344A (en) | 2018-11-21 | 2018-11-21 | Common mode current detection device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111208344A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3073825B2 (en) * | 1992-01-24 | 2000-08-07 | 日本放送協会 | Directional surge detector |
| CN1463483A (en) * | 2001-05-17 | 2003-12-24 | 国际整流器公司 | Active common mode filter connected in A-C line |
| US20160054360A1 (en) * | 2013-04-19 | 2016-02-25 | Mitsubishi Electric Corporation | Current measurement apparatus, device-behavior detection system, current measurement method, and program |
-
2018
- 2018-11-21 CN CN201811390750.9A patent/CN111208344A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3073825B2 (en) * | 1992-01-24 | 2000-08-07 | 日本放送協会 | Directional surge detector |
| CN1463483A (en) * | 2001-05-17 | 2003-12-24 | 国际整流器公司 | Active common mode filter connected in A-C line |
| US20160054360A1 (en) * | 2013-04-19 | 2016-02-25 | Mitsubishi Electric Corporation | Current measurement apparatus, device-behavior detection system, current measurement method, and program |
Non-Patent Citations (7)
| Title |
|---|
| 吕镇江: "模块化多电平变换器的综合控制策略研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 李行善: "《计算机测试与控制》", 31 January 1990, 北京航空航天大学出版社 * |
| 杨娜 等: "《传感器与测试技术》", 31 July 2012, 航空工业出版社 * |
| 武保同: "数字EPS应急系统若干技术的研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
| 肖芳 等: "《一体化电机系统中的电磁兼容》", 30 November 2017, 国防工业出版社 * |
| 袁鹏: "PWM逆变器有源共模EMI滤波器研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 魏兆博: "PWM逆变器共模电磁干扰分析及抑制技术研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7141960B2 (en) | Method and device system for testing electrical components | |
| CN103033667B (en) | Current measurement device and method | |
| CN202956428U (en) | Residual voltage testing device | |
| WO2021258763A1 (en) | Socket detection device and method supporting ground wire and zero wire anomaly detection | |
| CN105137157A (en) | Alternating- and direct-current high-voltage electricity testing device | |
| WO2021258731A1 (en) | Ground wire and neutral line abnormity detection method and device, | |
| CN2788207Y (en) | Battery short circuit testing device | |
| CN201707419U (en) | Coil turn-to-turn insulation detector | |
| CN110530408A (en) | A kind of Transducer-fault Detecting Method, detection circuit and detector | |
| CN111208344A (en) | Common mode current detection device and method | |
| CN217718079U (en) | Mutual inductor state monitoring circuit | |
| CN106291247A (en) | A kind of electric wire breakpoint location detection method | |
| CN110058072A (en) | A kind of electroscope with contact detection | |
| CN109085470A (en) | A kind of arc light sensor device and equipment health status judgment method | |
| CN106772003A (en) | A kind of load switch of transformer test system and method | |
| CN207924008U (en) | A kind of electroscope with contact detection | |
| CN208548756U (en) | Induction-type high-voltage charges indicators for switching condition | |
| CN103217560A (en) | Anti-stealing-electricity analysis meter | |
| CN103308744B (en) | High-tension cable gauze screen ground wire leakage current detector | |
| CN206132723U (en) | Air quality NFC detector | |
| CN220419445U (en) | Resistance discharge test fixture | |
| CN213423442U (en) | Socket detection circuit and socket detection device | |
| CN109298226A (en) | A kind of DC microammeter of more threshold values Intelligent acousto-optic alarms | |
| CN102998360B (en) | Online testing method for aging of transformer insulating oil based on electric field induction | |
| CN102928755A (en) | Hand-held insulativity detection device for line pole |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200529 |
|
| RJ01 | Rejection of invention patent application after publication |