CN117452164A - Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system - Google Patents
Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system Download PDFInfo
- Publication number
- CN117452164A CN117452164A CN202311529255.2A CN202311529255A CN117452164A CN 117452164 A CN117452164 A CN 117452164A CN 202311529255 A CN202311529255 A CN 202311529255A CN 117452164 A CN117452164 A CN 117452164A
- Authority
- CN
- China
- Prior art keywords
- current
- voltage
- lightning arrester
- signal
- signals
- 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
- 230000006698 induction Effects 0.000 title claims abstract description 17
- 230000005672 electromagnetic field Effects 0.000 title claims abstract description 10
- 238000000691 measurement method Methods 0.000 title claims description 3
- 238000000034 method Methods 0.000 claims abstract description 31
- 238000004364 calculation method Methods 0.000 claims abstract description 13
- 230000003321 amplification Effects 0.000 claims abstract description 11
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 11
- 238000009413 insulation Methods 0.000 claims abstract description 8
- 238000001914 filtration Methods 0.000 claims abstract description 7
- 230000004927 fusion Effects 0.000 claims abstract description 7
- 238000006243 chemical reaction Methods 0.000 claims abstract description 6
- 238000012545 processing Methods 0.000 claims abstract description 3
- 238000005259 measurement Methods 0.000 claims description 14
- 238000005070 sampling Methods 0.000 claims description 11
- 230000003750 conditioning effect Effects 0.000 claims description 10
- 238000004891 communication Methods 0.000 claims description 9
- 230000000087 stabilizing effect Effects 0.000 claims description 6
- 239000000284 extract Substances 0.000 claims description 3
- 230000001939 inductive effect Effects 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 abstract description 6
- 238000004458 analytical method Methods 0.000 abstract description 5
- 230000008859 change Effects 0.000 description 12
- 230000008569 process Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000005684 electric field Effects 0.000 description 5
- 238000001514 detection method Methods 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
-
- 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
- G01R15/144—Measuring arrangements for voltage not covered by other subgroups of G01R15/14
-
- 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
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/16—Spectrum analysis; Fourier analysis
- G01R23/165—Spectrum analysis; Fourier analysis using filters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R25/00—Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
- G01R25/02—Arrangements for measuring phase angle between a voltage and a current or between voltages or currents in circuits having distributed constants
-
- 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
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention relates to a method and a system for measuring resistive current of a distribution network type lightning arrester by non-invasive electromagnetic field cooperative induction, and belongs to the technical field of lightning arrester monitoring. The method comprises the steps of respectively acquiring voltage and current signals of a lightning arrester by a D-dot voltage sensor and a TMR current sensor, amplifying and filtering the acquired signals, and performing analog-to-digital conversion; processing the analog-digital converted signal through a phase-locked amplification algorithm to extract voltage and current signals from noise signal interference, and performing fast Fourier operation on the extracted voltage and current signals to obtain a phase difference between the voltage signals and the current signals, so as to calculate the resistive component of leakage current of the lightning arrester; and judging the insulation state of the lightning arrester according to the leakage current resistance component. According to the invention, the phase angle between the voltage and the current can be accurately obtained through fusion analysis and calculation of the measured voltage and the leakage current of the lightning arrester, and then the resistive current value is accurately calculated, so that the insulation state of the lightning arrester can be judged.
Description
Technical Field
The invention belongs to the field of lightning arrester leakage current monitoring, and relates to a method and a system for measuring resistive current of a distribution network type lightning arrester by non-invasive electromagnetic field cooperative induction.
Background
The distribution network type lightning arrester plays an important role in the distribution network, and the insulation state of the distribution network type lightning arrester is very important for the safe operation of the whole distribution station. However, in a long-term working state, the lightning arrester is affected by factors such as temperature, humidity, pollution and the like and power frequency voltage, the insulating property of the valve plate is reduced, the equivalent resistance is reduced, and the resistive current is increased accordingly. The resistive current and the capacitive current together form the leakage current of the lightning arrester, and the leakage current cannot be obviously changed when the resistive current is changed because the proportion of the resistive current is smaller. Therefore, in order to detect the insulation state of the lightning arrester and ensure the normal working and running of the lightning arrester, real-time measurement of the resistive current of the lightning arrester is required.
The existing lightning arrester resistive current measuring method generally adopts a leakage current full-current method, a capacitive current compensation method and a full-current full-voltage method.
1. Leakage current full current detection method: the special alternating current ammeter is connected in series to the grounding wire of the lightning arrester, so that the detection of the leakage current full current is realized. The change of the resistive component of the lightning arrester can be reflected through the monitoring of the full current, but the resistive component of the full current only accounts for 10% of the full current, so that the change trend is not obvious for the lightning arrester in the early stage of damp and gradually aging, and the defect is diagnosed in advance with certain difficulty.
2. Capacitive current compensation method: by utilizing the characteristic that the phase of the resistive leakage current is the same as that of the bus voltage of the circuit, the phase of the capacitive leakage current leads the phase of the bus voltage by 90 degrees, the external compensation circuit is used for providing reverse capacitive current, eliminating the capacitive current component and only retaining the resistive current component. However, in the actual operation process, due to electromagnetic interference in the surrounding environment, the measured value of the resistive current obtained after the capacitive current compensation deviates from the actual value, so that the operation state of the lightning arrester cannot be truly reflected by the capacitive current compensation method.
3. Full current full voltage method: by measuring the full voltage of the arrester using the PT sensor and the full current of the arrester using the CT sensor, since the phase of the resistive current is the same as that of the full voltage, the resistive current value can be calculated to reflect the operation state of the arrester by calculating the phase difference between the full voltage and the full current. However, during live detection, the voltage of the distribution network system may generate transient peak and overvoltage phenomena, which may cause inaccurate measurement results of the PT and may also cause damage to the PT.
Disclosure of Invention
Therefore, the invention aims to provide a method and a system for measuring resistive current of a distribution network type lightning arrester by non-invasive electromagnetic field cooperative induction, which are characterized in that a D-dot voltage sensor and a TMR current sensor are fused into a system, the system is arranged on the lightning arrester to measure the voltage and leakage current of the lightning arrester at the same time, and fusion analysis and calculation are carried out on the voltage and leakage current to obtain the resistive current value of the lightning arrester, so that the insulation state monitoring of the lightning arrester is realized, and effective help is provided for intelligent voltage construction.
In order to achieve the above purpose, the present invention provides the following technical solutions:
according to the scheme I, the resistive current measuring method of the distribution network type lightning arrester through non-invasive electromagnetic field cooperative induction calculates resistive current of the lightning arrester through the non-invasive electromagnetic field cooperative induction, specifically, a D-dot voltage sensor and a TMR current sensor are integrated into one device, and the device is arranged at the bottom of the lightning arrester to collect voltage signals and current signals of the lightning arrester with high precision; amplifying and filtering the acquired signals and then performing analog-to-digital conversion; then combining a phase-locked amplification algorithm and fast Fourier transformation to perform fusion analysis calculation on the voltage and current signals after analog-digital conversion to obtain a leakage current resistive component of the arrester, and improving calculation accuracy of the leakage current resistive component; and judging the insulation state of the lightning arrester according to the leakage current resistance component.
Further, the phase-locked amplifying algorithm specifically comprises: the phase-locked amplifying algorithm specifically comprises the following steps: the phase-locked amplifying algorithm specifically comprises the following steps: dividing the signal to be detected after analog-digital conversion into two paths, obtaining a reference signal with the same frequency as the signal to be detected, and equally dividing the reference signal into two paths; the signal to be measured in one path is multiplied by the reference signal and then is subjected to low-pass filtering to obtain an output signal V 1 (t); the reference signal of the other path is phase-shifted, multiplied by the signal to be detected of the other path, and then low-pass filtered to obtain an output signal V 2 (t)；V 1 (t) and V 2 (t) performing a cross-correlation operation.
The reference signal of the path of the phase shifting treatment needs to be shifted by 90 degrees.
Further, the resistive component of the leakage current is calculated by:
I r (k)＝I(k)sinδ
wherein I is r (k) Represents the resistive component of the leakage current, I (k) represents the leakage current of the arrester, and δ represents the phase difference of the voltage signal and the current signal.
The system comprises a front-end signal sensing module, a sampling circuit, a central control circuit, a wireless communication circuit, an upper computer and a power supply voltage stabilizing circuit which are sequentially connected. The front-end signal induction module is used for inducing voltage and current signals of the lightning arrester; the sampling circuit converts the voltage and current signals into digital signals and sends the digital signals to the central control circuit; the central control circuit performs phase-locking amplification noise reduction treatment on the digital signal, extracts the voltage and current values of the lightning arrester, and performs fusion calculation to obtain a leakage current resistance component and a capacitance component; the wireless communication circuit sends the resistive component and the capacitive component of the leakage current to the upper computer for display; the power supply voltage stabilizing circuit provides stable working voltage with small noise interference for the front end signal sensing module, the sampling circuit, the central control circuit and the wireless communication circuit.
Optionally, the front-end signal sensing module comprises a D-dot voltage sensor, a TMR current sensor and a signal conditioning circuit; the D-dot voltage sensor and the TMR current sensor respectively sense voltage signals and current signals of the lightning arrester and transmit the voltage signals and the current signals to the signal conditioning circuit; the signal conditioning circuit amplifies and filters the voltage and current signals and transmits the signals to the sampling circuit.
The invention has the beneficial effects that:
(1) The invention integrates the D-dot voltage sensor and the TMR sensor, and in the use process, the sensor is only required to be arranged at the bottom of the lightning arrester without being in direct contact with a tested conductor, and the lightning arrester voltage and the lightning arrester current can be directly measured by passing the lightning arrester grounding wire through the D-dot voltage sensor and the TMR current sensor, so that the operation is simple and convenient; the invention can accurately measure the resistive current value based on the characteristics of good transient characteristic of the D-dot voltage sensor and high weak current measurement precision of the TMR current sensor. Compared with the existing full-voltage and full-current method which needs to be independently provided with the PT voltage sensor and the CT current sensor, the method is simpler and more convenient to operate and smaller in size.
(2) According to the invention, a phase-locked amplification algorithm and an FFT algorithm are combined and applied to calculation of the resistive current value of the lightning arrester, and the phase angle between the voltage and the current can be accurately obtained through fusion analysis and calculation of the measured voltage and leakage current of the lightning arrester, so that the resistive current value can be accurately calculated.
(3) According to the invention, the calculated resistive current value can be remotely transmitted to the upper computer through the wireless communication circuit, so that the inconvenience that a worker needs to check the result on site is solved, and the potential danger caused by sudden action of the lightning arrester possibly faced by the maintainer in the operation process is avoided.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.
Drawings
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in the following preferred detail with reference to the accompanying drawings, in which:
FIG. 1 is a schematic illustration of an arrester resistive current measurement system incorporating voltage and current sensors provided in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a D-dot voltage sensor;
FIG. 3 is a schematic diagram of a TMR current sensor;
FIG. 4 is a schematic diagram of a front end signal sensing module;
FIG. 5 is a schematic diagram of a voltage and current sensor installation;
FIG. 6 is a schematic diagram of a phase-locked amplification algorithm calculation process;
FIG. 7 is a schematic diagram of the measurement flow of the present invention.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.
Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to limit the invention; for the purpose of better illustrating embodiments of the invention, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numbers in the drawings of embodiments of the invention correspond to the same or similar components; in the description of the present invention, it should be understood that, if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc., that indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but not for indicating or suggesting that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, so that the terms describing the positional relationship in the drawings are merely for exemplary illustration and should not be construed as limiting the present invention, and that the specific meaning of the above terms may be understood by those of ordinary skill in the art according to the specific circumstances.
The invention uses the D-dot voltage sensor to indirectly detect the change of the electric field by measuring the change of the capacitance by utilizing the electric field coupling principle, thereby realizing the measurement and monitoring of the voltage signal. The structure of the D-dot voltage sensor is shown in fig. 2, and is a multiple electrode parallel structure, and each electrode is designed into concentric circles to improve the sensitivity of the sensor. The high-voltage end outgoing line of the lightning arrester passes through the sensor, and when the sensor is exposed to an electric field emitted by the high-voltage end outgoing line, the electric field can enable electric charge accumulation or distribution on the electrode to change. The change of the electric charge accumulation or distribution in the sensor can cause the change of the capacitance between the electrodes, and the change condition of the electric field can be indirectly obtained by measuring the change of the capacitance, so that the magnitude of the voltage signal can be deduced.
The TMR current sensor utilizes the magnetic field induction principle to indirectly detect the change of a magnetic field by measuring the change of internal magnetic resistance, thereby realizing the measurement and monitoring of current. The current sensor can adopt a TMR2905 chip as a magnetic field induction unit, and uses a magnetic focusing ring to amplify the magnetic field of the conducting wire, and the structure of the TMR current sensor is shown in fig. 3. When the grounding wire of the lightning arrester passes through the magnetic ring, stray magnetic fields emitted from the periphery are amplified by the magnetic focusing ring, fine changes of the magnetic field are induced, and the changes of the magnetic field are converted and output into voltage changes through the TMR2905 chip, so that the change rule of leakage current of the lightning arrester is obtained.
The invention combines the advantages of good transient characteristic of the D-dot voltage sensor and high weak current measurement precision of the TMR current sensor to form the system front-end signal sensing module shown in figure 4. The front-end signal induction module is arranged on the lightning arrester, so that a voltage and current signal can be obtained through induction. On the basis of the front-end signal induction module, a signal conditioning circuit, an ADC sampling circuit, a central control circuit, a wireless communication circuit, a power supply voltage stabilizing circuit and an upper computer are configured to form the non-invasive electromagnetic field collaborative induction distribution network type lightning arrester resistive current measurement system shown in figure 1.
The main operation of the lightning arrester resistive current measurement system shown in fig. 1 is as shown in fig. 7, and includes:
(1) Installing a D-dot voltage sensor and a TMR current sensor at the bottom of the lightning arrester in a mode shown in figure 5, inducing to obtain voltage and current signals, and transmitting the voltage and current signals to a signal conditioning circuit through a signal transmission line;
(2) The signal conditioning circuit is used for respectively amplifying and filtering the voltage and current signals input by the sensor;
(3) The ADC sampling circuit converts the voltage and current signals subjected to amplification and filtering treatment into digital signals through two analog channels and sends the digital signals to the central control circuit;
(4) The central control circuit performs phase-locking amplification noise reduction treatment on the sampled digital signals, extracts a lightning arrester voltage value and a lightning arrester current value from a strong noise background, and performs fusion calculation to obtain a leakage current resistance component and a capacitance component;
(5) The wireless communication circuit sends the calculated leakage current resistive component and capacitive component to an upper computer for display through a wireless network;
(6) The power supply voltage stabilizing circuit provides stable working voltage with small noise interference for the whole system.
In step (4), the process of calculating the resistive current by the central control circuit fusing the D-dot voltage sensor and the TMR sensor is as follows:
firstly, in order to ensure the accuracy of data, a phase-locked amplifying algorithm is required to be applied to a digital signal obtained through ADC sampling so as to extract voltage and current signals from noise signal interference existing in a circuit, the calculation process is shown in fig. 6, the main calculation principle is cross-correlation operation, and a signal to be detected with a noise signal and a reference signal cross-correlated with the signal to be detected are required to be input simultaneously in the working process. The embodiment inputs the signal to be testedAnd co-frequency reference signal->For example, a process of eliminating noise signals in a circuit by a lock-in amplification algorithm is specifically described. Wherein n is 1 (t) and n 2 And (t) is a noise interference signal present in the signal.
As shown in fig. 6, the reference signal is first multiplied by the signal to be measured, passed through a low-pass filter, and the residual noise is ignored, resulting in the following formula (1):
wherein A and B respectively represent the amplitudes of the signal to be measured and the reference signal, f represents the frequencies of the signal to be measured and the reference signal,and->Respectively representing the phases of the signal under test and the reference signal.
As can be seen from the equation (1), when the signal to be detected is in phase with the reference signal, the phase-locked amplifying algorithm outputs the signal to be detected with the highest accuracy. However, it is difficult to ensure that the phases are the same in the actual process, so in order to ensure that the final operation result is not affected by the different phases, two mutually orthogonal signals are obtained through the phase shifting operation as shown in fig. 6, and the cross correlation operation is performed to obtain an output signal proportional to the amplitude of the external signal to be detected, as shown in the following formula:
then, carrying out Fourier series decomposition on the voltage and current signals extracted from the noise signals to obtain:
in U 0 Representing the DC voltage component, I 0 Representing a direct current component; u (U) k Representing the magnitude of the k harmonic component voltage; i k Representing the current amplitude of the k harmonic component;representing the initial phase angle of the k-th harmonic component voltage; />Representing the k-th harmonic component current phase angle.
In order to obtain the phase removal angle of the current and the voltage more accurately, the phase information in the fundamental wave signal is utilized to obtain the following formula according to a trigonometric differential function and Fourier transformation in a discrete period:
where U (k) represents the kth harmonic of the voltage signal, I (k) represents the kth harmonic of the current signal, and N represents the sequence period, whereby the phase angle of the voltage current represented by the following formula can be obtained:
thereby obtaining the phase angle delta and the resistive component I r (k) And capacitive component I c (k) Is represented by the following formula:
in actual operation, the frequency of the reference signal is set at 50Hz, and the frequency is kept the same as the power frequency of the target signal in the normal working state. In the working state, the noise extraction processing and the phase difference calculation are carried out on the signals obtained by the lightning arrester resistive current measurement system through the phase-locked amplification operation and the FFT analysis, so that the resistive current component under each subharmonic of the leakage current can be obtained, the calculated result is sent to an upper computer, the resistive current component of the lightning arrester can be monitored remotely, and the insulation state of the lightning arrester can be judged.
Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the claims of the present invention.
Claims (7)
1. A non-invasive electromagnetic field cooperative induction distribution network type lightning arrester resistive current measurement method is characterized by comprising the following steps of: the method calculates the resistive current of the lightning arrester through the non-invasive electromagnetic field cooperative induction, specifically, a D-dot voltage sensor and a TMR current sensor are integrated into a device, and the device is arranged at the bottom of the lightning arrester to collect the voltage signal and the current signal of the lightning arrester with high precision; amplifying and filtering the acquired signals and then performing analog-to-digital conversion; the phase-locked amplification algorithm is used for processing the analog-to-digital converted signals to extract voltage and current signals from noise signal interference, and then the extracted voltage and current signals are subjected to fast Fourier operation to obtain phase differences of the voltage signals and the current signals, so that the resistive component of the leakage current of the arrester is calculated; and judging the insulation state of the lightning arrester according to the leakage current resistance component.
2. The method for measuring resistive current of distribution network type lightning arresters according to claim 1, wherein the method comprises the following steps: the phase-locked amplifying algorithm specifically comprises the following steps: dividing the signal to be detected after analog-digital conversion into two paths, obtaining a reference signal with the same frequency as the signal to be detected, and equally dividing the reference signal into two paths; the signal to be measured in one path is multiplied by the reference signal and then is subjected to low-pass filtering to obtain an output signal V 1 (t); the reference signal of the other path is phase-shifted, multiplied by the signal to be detected of the other path, and then low-pass filtered to obtain an output signal V 2 (t)；V 1 (t) and V 2 (t) performing a cross-correlation operation.
3. The method for measuring resistive current of distribution network type lightning arresters according to claim 2, wherein the method comprises the following steps: the reference signal requiring phase shifting is 90 deg. phase shifted.
4. The method for measuring resistive current of distribution network type lightning arresters according to claim 1, wherein the method comprises the following steps: the resistive component of the leakage current is calculated by:
I r (k)＝I(k)sinδ
wherein I is r (k) Represents the resistive component of the leakage current, I (k) represents the leakage current of the arrester, and δ represents the phase difference of the voltage signal and the current signal.
5. A distribution network type lightning arrester resistive current measurement system suitable for the method of any one of claims 1 to 4, characterized in that: the system comprises a front-end signal sensing module, a sampling circuit, a central control circuit, a wireless communication circuit and an upper computer which are connected in sequence; the front-end signal induction module is used for inducing voltage and current signals of the lightning arrester; the sampling circuit is used for converting the voltage and current signals into digital signals and sending the digital signals to the central control circuit; the central control circuit performs phase-locking amplification noise reduction treatment on the digital signal, extracts the voltage and current values of the lightning arrester, and performs fusion calculation to obtain a leakage current resistance component and a capacitance component; and the wireless communication circuit sends the resistive component and the capacitive component of the leakage current to the upper computer for display.
6. The distribution network type lightning arrester resistive current measurement system according to claim 5, wherein: the front-end signal sensing module comprises a D-dot voltage sensor, a TMR current sensor and a signal conditioning circuit; the D-dot voltage sensor and the TMR current sensor respectively sense voltage signals and current signals of the lightning arrester and transmit the voltage signals and the current signals to the signal conditioning circuit; the signal conditioning circuit amplifies and filters the voltage and current signals and transmits the signals to the sampling circuit.
7. The distribution network type lightning arrester resistive current measurement system according to claim 5, wherein: the system also comprises a power supply voltage stabilizing circuit, wherein the power supply voltage stabilizing circuit provides stable working voltage for the front-end signal conditioning module, the sampling circuit, the central control circuit and the wireless communication circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311529255.2A CN117452164A (en) | 2023-11-16 | 2023-11-16 | Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311529255.2A CN117452164A (en) | 2023-11-16 | 2023-11-16 | Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117452164A true CN117452164A (en) | 2024-01-26 |
Family
ID=89596630
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311529255.2A Pending CN117452164A (en) | 2023-11-16 | 2023-11-16 | Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117452164A (en) |
-
2023
- 2023-11-16 CN CN202311529255.2A patent/CN117452164A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9207198B2 (en) | Electrical tomography apparatus and method and current driver | |
| CN101663589B (en) | Measuring instrument for a resistive electric leakage current | |
| CN111722044B (en) | Direct current charging pile testing method, device and equipment based on frequency sweep calibration shunt | |
| CN104296786A (en) | Digital bridge capacitive measuring module | |
| US20130154674A1 (en) | Method of high voltage detection and accurate phase angle measurement in cordless phasing meters | |
| CN113358914B (en) | Voltage measurement circuit, voltage measurement method thereof and voltage measurement equipment | |
| US6225810B1 (en) | Loop resistance tester (LRT) for cable shield integrity | |
| CN102156214B (en) | Double-light-path leakage current optical fiber sensor device | |
| EP3244217A2 (en) | Electric current measurement apparatus | |
| CN110488065A (en) | A kind of high-voltage signal acquisition system based on optical fiber transmission | |
| CN109506802A (en) | A kind of reactor temperature sensing circuit | |
| CN100460883C (en) | Detection method for testing current in resistance property of lightning arrester | |
| CN117452164A (en) | Non-invasive electromagnetic field cooperative induction type distribution network type lightning arrester resistive current measurement method and system | |
| Shenil et al. | An auto-balancing scheme for non-contact ac voltage measurement | |
| CN203519717U (en) | H type filtering capacitor bank imbalance current detection apparatus | |
| CN205539178U (en) | Current detection device is revealed to electric heat plastic film | |
| CN213302350U (en) | Metal zinc oxide arrester resistive current rapid measurement device | |
| CN112526437A (en) | Real-time acquisition system for running state of high-voltage transformer group | |
| CN103513096A (en) | H type filter capacitor group imbalance current detection device | |
| CN219285262U (en) | High-precision alternating current impedance detection equipment | |
| CN217278623U (en) | Line load network detection and fault positioning device | |
| CN213581144U (en) | High-sensitivity ground wire impedance detection circuit | |
| CN110672927B (en) | Voltage fitting method based on target | |
| CN219871552U (en) | Signal detection device for frequency domain dielectric spectrum tester | |
| CN111830322B (en) | GIL conductor electric connection state evaluation device |
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 |