CN117907762A - Ultrahigh frequency partial discharge detection method and device - Google Patents
Ultrahigh frequency partial discharge detection method and device Download PDFInfo
- Publication number
- CN117907762A CN117907762A CN202311737096.5A CN202311737096A CN117907762A CN 117907762 A CN117907762 A CN 117907762A CN 202311737096 A CN202311737096 A CN 202311737096A CN 117907762 A CN117907762 A CN 117907762A
- Authority
- CN
- China
- Prior art keywords
- frequency
- signal
- partial discharge
- receiver
- bandwidth
- 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
- 238000001514 detection method Methods 0.000 title claims abstract description 79
- 238000007689 inspection Methods 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 15
- 238000003745 diagnosis Methods 0.000 claims abstract description 11
- 238000006243 chemical reaction Methods 0.000 claims description 18
- 238000001914 filtration Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 claims description 5
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000003044 adaptive effect Effects 0.000 claims 1
- 230000008901 benefit Effects 0.000 abstract description 5
- 230000007547 defect Effects 0.000 abstract description 5
- 238000012360 testing method Methods 0.000 abstract description 3
- 239000002245 particle Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000002068 genetic effect Effects 0.000 description 3
- 239000012212 insulator Substances 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000035772 mutation Effects 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Landscapes
- Testing Relating To Insulation (AREA)
Abstract
The invention discloses an ultrahigh frequency partial discharge detection method and device, belongs to the technical field of ultrahigh frequency partial discharge detection, and aims to overcome the defect that the existing ultrahigh frequency partial discharge detection method is difficult to well inhibit external interference and avoid missing discharge characteristic peaks. The detection method comprises the following steps: placing an antenna in the shielding cavity, and then receiving a detection signal through the antenna; the receiver adjusts frequency points and bandwidth based on the whole bandwidth of the inspection signal, and each frequency point is detected by adopting an ultrahigh frequency narrow-band detection method; converting the inspection signal into a digital signal; the data display terminal displays the received digital signals and transmits the obtained digital signals back to the partial discharge fault diagnosis system; solving a time delay establishment equation, and then positioning the space of the partial discharge source. The method and the device can realize the sweep test of each frequency point in the whole large bandwidth, and realize the advantages of the ultra-high frequency narrow-band detection method and the ultra-high frequency broadband detection method.
Description
Technical Field
The invention belongs to the technical field of ultrahigh frequency partial discharge detection, and relates to an ultrahigh frequency partial discharge detection method and device.
Background
During the use of electrical equipment, insulation system faults and power failure accidents often occur. The current effective evaluation method is verified through a partial discharge test and objectively reflects the working state of the electrical equipment. Partial discharge is a partial discharge phenomenon caused by breakage or breakdown of an insulator, reflects deterioration of the insulator and unstable pressure, and is affected by internal and external factors during production and service to deteriorate insulation conditions in local areas. Normally, partial discharges do not lead to damage of the dielectric integrity, but can significantly affect the reliability of the insulator, eventually leading to permanent equipment failure if the electrical equipment is out of service and inspected for a long period of time. At present, the stability of a power grid and the compliance operation of electrical equipment are the precondition of the social stable operation, so that the research on the partial discharge detection of the electrical equipment is made, and the method has great economic benefit and time significance.
When partial discharge occurs in the power equipment, electromagnetic waves with different frequencies can be radiated. When the discharge gap is smaller and the time is shorter, the steepness of the current pulse is larger, the current pulse can excite electromagnetic waves with the frequency of several GHz inside, and the ultrahigh frequency detection method realizes the partial discharge detection by detecting the electromagnetic signals. The detection frequency band of the method is the ultrahigh frequency band (300 MHz-3 GHz), so the detection method is named as an ultrahigh frequency detection method.
The ultrahigh frequency detection method is suitable for on-line monitoring of partial discharge due to good corona resistance, and particularly, along with the rapid development of on-line monitoring of partial discharge in recent years, the ultrahigh frequency detection method is more and more widely applied to the on-line monitoring of partial discharge of electrical equipment. The ultra-high frequency detection method mainly comprises two technical means, namely an ultra-high frequency narrow-band detection method and an ultra-high frequency broadband detection method.
The center frequency measured by the ultra-high frequency narrowband detection method is usually hundreds of MHz, the bandwidth is tens of MHz, for example, the center frequency is 600MHz, the bandwidth is 100MHz, the frequency band fed into the detection system is 550-650 MHz, the narrowband detection method can arbitrarily select the frequency band, so that a plurality of interferences on site can be avoided, the external interference can be effectively restrained, the signal to noise ratio can be improved, but the signal in a narrower frequency band is detected, and the energy of the detection signal can be limited.
And the ultra-high frequency broadband detection rule sends all signals in the detection frequency band into the detection system, so that the information quantity is large under the condition, partial discharge can be detected in a sufficiently wide frequency range, and missing of discharge characteristic peaks is avoided. However, if there is an interference signal in the detection frequency band, the signal to noise ratio is low, which affects the subsequent analysis.
Disclosure of Invention
The invention provides an ultrahigh frequency partial discharge detection method and device aiming at the problems existing in the prior art, and aims to overcome the defect that the existing ultrahigh frequency partial discharge detection method is difficult to well inhibit external interference and avoid missing discharge characteristic peaks.
The invention is realized in the following way:
1. a method for detecting ultrahigh frequency partial discharge comprises the following steps:
Step 1, placing an antenna on a wide-bandwidth microwave signal receiver with a variable bandwidth frequency point in a shielding cavity, and then receiving a detection signal through the antenna;
Step 2, the receiver adjusts frequency points and bandwidth based on the whole bandwidth of the inspection signal, detects each frequency point by adopting an ultra-high frequency narrow-band detection method, and amplifies and filters the received inspection signal;
step 3, an analog-to-digital conversion module in the receiver processes the amplified and filtered inspection signals of the receiver and converts the signals into digital signals;
Step 4, the data display terminal displays the received digital signals and transmits the obtained digital signals back to the partial discharge fault diagnosis system;
step 5, placing the antennas of a plurality of receivers at different positions, and repeating the steps 1 to 4;
And 6, establishing an equation by solving time delay between receivers placed at different positions, then performing spatial positioning of the partial discharge source by using a spatial positioning algorithm, and finally determining the position, type and severity of partial discharge.
In step 2, the receiver sequentially performs noise filtering, amplifying, up-converting, noise filtering and down-converting on the inspection signal.
And adjusting the detection frequency point of the receiver by adjusting a first oscillator on the receiver, and then performing up-conversion processing on the inspection signal by the receiver.
The detection bandwidth after down-conversion is adjusted by adjusting a variable bandwidth active filter on the receiver.
The receiver down-converts the signal to 0Hz.
The partial discharge fault diagnosis system adopts an LMS-based self-adaptive time delay estimation method to acquire time delay signals among different receivers.
An ultrahigh frequency partial discharge detection device comprising:
The receiver is provided with an antenna and is used for receiving the inspection signal, and the receiver is a large-bandwidth microwave signal receiver with variable bandwidth frequency conversion points and performs noise filtering, amplification, up-conversion, noise filtering, down-conversion, detection bandwidth adjustment and analog-to-digital conversion processing on the inspection signal;
the data display terminal displays the digital signals transmitted by the receiver;
And the data display terminal transmits the obtained digital signals back to the partial discharge fault diagnosis system, an equation is established by solving time delay among receivers placed at different positions, then the spatial positioning of the partial discharge source is carried out by utilizing a spatial positioning algorithm, and finally the position, the type and the severity of the partial discharge are determined.
The receiver comprises a first band-pass filter, a large-bandwidth low-noise amplifier connected with the first band-pass filter, a first mixer connected with the large-bandwidth low-noise amplifier, and a first oscillator connected with the first mixer, so that a detection signal received by the antenna is transmitted to the first band-pass filter for noise filtering, amplified by the large-bandwidth low-noise amplifier and enters the first mixer, the first oscillator inputs a first local oscillator signal to the first mixer, the first mixer up-converts the detection signal and outputs a high intermediate frequency signal, and the frequency of the high intermediate frequency signal is higher than the highest working frequency of the detection signal received by the antenna.
The receiver further comprises a second band-pass filter connected with the first frequency mixer, a second frequency mixer connected with the second band-pass filter, a second oscillator connected with the second frequency mixer and a variable bandwidth active filter, the high intermediate frequency signal is input into the second frequency mixer after passing through the second band-pass filter, the second oscillator inputs a second local oscillation signal into the second frequency mixer, and the second frequency mixer down-converts the high intermediate frequency signal to obtain a zero intermediate frequency signal and inputs the zero intermediate frequency signal into the variable bandwidth active filter.
The first mixer is a double-balanced mixer, a radio frequency port of the first mixer is connected with the large-bandwidth low-noise amplifier in parallel, and a local oscillator port of the first mixer is connected with the first oscillator in anti-parallel.
The ultrahigh frequency partial discharge detection method and the ultrahigh frequency partial discharge detection device provided by the invention can realize the sweep frequency test of each frequency point in the whole large bandwidth, and realize the advantages of the ultrahigh frequency narrowband detection method and the ultrahigh frequency broadband detection method.
Drawings
Fig. 1 is a block diagram of a receiver;
FIG. 2 is a schematic diagram of three characteristic peaks detected;
FIG. 3 is a schematic diagram of an application frequency range;
Fig. 4 is a schematic diagram of partial discharge position location.
Detailed Description
The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, so that the technical scheme of the present invention can be understood and mastered more easily. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
The embodiment provides an ultrahigh frequency partial discharge detection method and device, wherein the ultrahigh frequency partial discharge detection device comprises a receiver, a data display terminal and a partial discharge fault diagnosis system, and the detection method comprises the following steps:
And step 1, placing an antenna on the wide-bandwidth microwave signal receiver with the variable bandwidth frequency point in a shielding cavity, and then receiving a detection signal through the antenna, wherein the shielding cavity can reduce signal interference.
And 2, the receiver adjusts frequency points and bandwidth based on the whole bandwidth of the inspection signal, detects each frequency point by adopting an ultrahigh frequency narrow-band detection method, and amplifies and filters the received inspection signal. The radio spectrum is divided into 14 bands with a highest to lowest frequency ratio of 10 for each band. The frequency band with the highest and lowest frequency ratio lower than 10 is called narrow band, broadband or ultra-broadband, and the frequency band with the highest and lowest frequency ratio is called large bandwidth with the highest and lowest frequency ratio being more than or equal to 10.
The receiver can receive the microwave signal with the highest and lowest frequency ratio being more than or equal to 3000. As shown in fig. 1, the receiver includes a first band-pass filter, a high-bandwidth low-noise amplifier connected to the first band-pass filter, a first mixer connected to the high-bandwidth low-noise amplifier, a first oscillator connected to the first mixer, a second band-pass filter connected to the first mixer, a second mixer connected to the second band-pass filter, a second oscillator connected to the second mixer, and a variable-bandwidth active filter, so that a detected signal received by the antenna is transmitted to the first band-pass filter to perform noise filtering, and then amplified by the high-bandwidth low-noise amplifier, and then enters the first mixer, the first oscillator inputs the first local oscillator signal to the first mixer, the first mixer up-converts the detected signal and outputs a high intermediate frequency signal, and the frequency of the high intermediate frequency signal is higher than the highest working frequency of the detected signal received by the antenna. The high intermediate frequency signal is input into a second mixer after passing through a second band-pass filter, a second oscillator inputs a second local oscillation signal to the second mixer, and the second mixer down-converts the high intermediate frequency signal to obtain a zero intermediate frequency signal and inputs the zero intermediate frequency signal into a variable bandwidth active filter.
For further explanation, a microwave signal having a sample signal of 1MHz to 30GHz is taken as an example. After a microwave signal of 1MHz-30GHz is received by an antenna, noise filtering is carried out by a first band-pass filter, then the received signal is amplified by a large-bandwidth low-noise amplifier, and then the amplified signal is up-converted to 60GHz (namely, a high intermediate frequency signal IF1=60 GHz) by a first mixer, and the frequency range of the first oscillator is 60.001GHz-90GHz. The detection frequency point can be changed only by changing the frequency of the first oscillator. The frequency of the high intermediate frequency signal IF1 obtained by up-conversion by the first mixer is higher than the highest operating frequency of the inspection signal, for example, the highest frequency of the inspection signal is 30GHz, and the high intermediate frequency signal IF1 is 60GHz.
The obtained high intermediate frequency signal IF1 is filtered again by a second band-pass filter to further eliminate interference, and then the signal of the high intermediate frequency signal IF1 is input into a second mixer to be subjected to down-conversion to obtain a zero intermediate frequency signal if2=0 Hz. The frequency of the second oscillator is 60GHz at this time. And then inputting the obtained down-conversion signal into a variable bandwidth active filter, wherein the detection bandwidth is variable only by changing the bandwidth of the variable bandwidth active filter, and the bandwidth change range of the variable bandwidth active filter is 3MHz-50MHz.
The high intermediate frequency signal IF1 is higher than the highest microwave working frequency, so that the corresponding image interference frequency is not in the frequency range of the input radio frequency signal, and the image interference problem is avoided. Then, the high intermediate frequency signal IF1 generated by the high intermediate frequency structure is directly down-converted to a zero intermediate frequency signal IF2 with zero center frequency, and the direct current deviation is eliminated by adopting an alternating current coupling method.
The first mixer is a double-balanced mixer, a radio frequency port of the first mixer is connected with the large-bandwidth low-noise amplifier in parallel, and a local oscillator port of the first mixer is connected with the first oscillator in anti-parallel.
As shown in fig. 2, the ultrahigh frequency partial discharge detection method of the large-bandwidth microwave signal receiver based on the variable frequency point of the bandwidth can realize the detection of the characteristic peak 1, the characteristic peak 2 and the characteristic peak 3 by changing the measurement frequency point and the measurement bandwidth in the frequency range of 2MHz-2GHz, can not miss the characteristic peak, and can effectively inhibit external interference.
The prior art adopts a mode of detecting partial discharge in the frequency division of high frequency (3 MHz-30 MHz), very high frequency (30 MHz-300 MHz) and ultra-high frequency (300 MHz-3 GHz), and the ultra-high frequency partial discharge detection method of the large-bandwidth microwave signal receiver based on the variable frequency point of the bandwidth can simultaneously cover the detection of high frequency, very high frequency and ultra-high frequency partial discharge frequency spectrums (3 MHz-3 GHz), as shown in figure 3. It should be noted that the wide bandwidth microwave signal receiver with variable bandwidth frequency points not only can realize the selection of any frequency point and bandwidth within the frequency range of 3MHz-3 GHz, but also can be expanded to any wider frequency range in principle.
And step 3, an analog-to-digital conversion module in the receiver performs signal processing on the amplified and filtered inspection signal of the receiver to convert the signal into a digital signal.
And 4, the data display terminal displays the received digital signals and transmits the obtained digital signals back to the partial discharge fault diagnosis system. For example, the detection frequency point set by the receiver is 500MHz, and the detection bandwidth is 100MHz. The frequency band fed into the data display terminal and the partial discharge fault diagnosis system is 450-550MHz.
Step 5, placing the antenna and the receiver at different positions, and repeating the steps 1 to 4;
And 6, establishing an equation by solving time delay between receivers placed at different positions, then performing spatial positioning of the partial discharge source by using a spatial positioning algorithm, and finally determining the position, type and severity of partial discharge. The partial discharge fault diagnosis system adopts an LMS-based self-adaptive time delay estimation method to acquire time delay signals among different receivers. As shown in fig. 4, the positions of the antennas of different receivers from S 1、S2、S3、S4 to S n in the figure can accurately locate the partial discharge position P.
The invention hybridizes the particle swarm algorithm with the genetic algorithm, namely proposes that the PSO-GA algorithm is used for the space positioning calculation of the local discharge source. The particle swarm algorithm is an algorithm that solves an optimal solution by simulating the movement of particles in space. While genetic algorithms are algorithms that find the optimal solution by simulating the process of biological evolution. The invention combines the two organically to form the PSO-GA algorithm. In the PSO-GA algorithm, the particle flight of the particle swarm algorithm is replaced by crossover and mutation of the genetic algorithm. The mutation operation ensures diversity, and the cross operation inherits part of the optimal solution. This allows the algorithm to have a more optimal effect and to find the spatial position of the partial discharge source faster.
The detection method not only solves the defect that the ultra-high frequency narrow-band detection method omits other characteristic peaks, but also solves the defect that the subsequent signal analysis and processing are affected by low signal-to-noise ratio caused by the fact that the ultra-high frequency broadband detection method comprises a large amount of interference signals. On the one hand, the partial discharge can be detected in a frequency range which is wide enough, and missing discharge characteristic peaks is avoided. On the other hand, the arbitrary selection of the measuring frequency band can be realized in a wide enough frequency range, so that a plurality of interferences on site can be effectively avoided, the external interferences can be effectively restrained, the signal to noise ratio can be improved, and the subsequent identification and positioning of the discharge defect type can be facilitated. The ultrahigh frequency partial discharge detection method based on the wide-bandwidth microwave signal receiver with the variable frequency point of the bandwidth can simultaneously take the advantages of the ultrahigh frequency narrow-band detection method and the ultrahigh frequency broadband detection method into consideration.
The prior art adopts a mode of detecting partial discharge respectively in the frequency division of high frequency (3 MHz-30 MHz), very high frequency (30 MHz-300 MHz) and ultra-high frequency (300 MHz-3 GHz), and the detection method can simultaneously cover the detection of high frequency, very high frequency and ultra-high frequency partial discharge frequency spectrum (3 MHz-3 GHz).
The detection method not only can simultaneously consider the advantages of the ultra-high frequency narrow-band detection method and the ultra-high frequency broadband detection method, but also can establish an equation by solving the time delay between receivers placed at different positions, and then utilizes a space positioning algorithm to perform the space positioning of the partial discharge source, thereby realizing the accurate positioning of the partial discharge position.
Claims (10)
1. The ultrahigh frequency partial discharge detection method is characterized by comprising the following steps of:
Step 1, placing an antenna on a wide-bandwidth microwave signal receiver with a variable bandwidth frequency point in a shielding cavity, and then receiving a detection signal through the antenna;
Step 2, the receiver adjusts frequency points and bandwidth based on the whole bandwidth of the inspection signal, detects each frequency point by adopting an ultra-high frequency narrow-band detection method, and amplifies and filters the received inspection signal;
step 3, an analog-to-digital conversion module in the receiver processes the amplified and filtered inspection signals of the receiver and converts the signals into digital signals;
Step 4, the data display terminal displays the received digital signals and transmits the obtained digital signals back to the partial discharge fault diagnosis system;
step 5, placing the antennas of a plurality of receivers at different positions, and repeating the steps 1 to 4;
And 6, establishing an equation by solving time delay between receivers placed at different positions, then performing spatial positioning of the partial discharge source by using a spatial positioning algorithm, and finally determining the position, type and severity of partial discharge.
2. The method according to claim 1, wherein in step 2, the receiver sequentially performs noise filtering, amplification, up-conversion, noise filtering, and down-conversion on the inspection signal.
3. The method of claim 2, wherein the receiver adjusts the detection frequency of the receiver by adjusting a first oscillator on the receiver, and then the receiver up-converts the detected signal.
4. The method of claim 2, wherein the down-converted detection bandwidth is adjusted by adjusting a variable bandwidth active filter on the receiver.
5. The method of claim 2, wherein the receiver down-converts the signal to 0Hz.
6. The method of claim 1, wherein the partial discharge fault diagnosis system uses an LMS-based adaptive delay estimation method to obtain delay signals between different receivers.
7. An ultrahigh frequency partial discharge detection device, comprising:
The receiver is provided with an antenna and is used for receiving the inspection signal, and the receiver is a large-bandwidth microwave signal receiver with variable bandwidth frequency conversion points and performs noise filtering, amplification, up-conversion, noise filtering, down-conversion, detection bandwidth adjustment and analog-to-digital conversion processing on the inspection signal;
the data display terminal displays the digital signals transmitted by the receiver;
And the data display terminal transmits the obtained digital signals back to the partial discharge fault diagnosis system, an equation is established by solving time delay among receivers placed at different positions, then the spatial positioning of the partial discharge source is carried out by utilizing a spatial positioning algorithm, and finally the position, the type and the severity of the partial discharge are determined.
8. The device according to claim 1, wherein the receiver comprises a first band-pass filter, a high-bandwidth low-noise amplifier connected to the first band-pass filter, a first mixer connected to the high-bandwidth low-noise amplifier, and a first oscillator connected to the first mixer, so that the inspection signal received by the antenna is transmitted to the first band-pass filter for noise filtering, amplified by the high-bandwidth low-noise amplifier, and then enters the first mixer, the first oscillator inputs the first local oscillator signal to the first mixer, the first mixer up-converts the inspection signal and outputs a high intermediate frequency signal, and the frequency of the high intermediate frequency signal is higher than the highest working frequency of the inspection signal received by the antenna.
9. The uhf partial discharge detection device of claim 8, wherein the receiver further comprises a second bandpass filter coupled to the first mixer, a second mixer coupled to the second bandpass filter, a second oscillator coupled to the second mixer, and a variable bandwidth active filter, the high intermediate frequency signal is input to the second mixer after passing through the second bandpass filter, the second oscillator inputs a second local oscillator signal to the second mixer, and the second mixer down-converts the high intermediate frequency signal to a zero intermediate frequency signal and inputs the zero intermediate frequency signal to the variable bandwidth active filter.
10. The uhf partial discharge detection device of claim 9, wherein the first mixer is a double balanced mixer, a radio frequency port of the first mixer is connected in parallel with the large bandwidth low noise amplifier, and a local oscillator port is connected in anti-parallel with the first oscillator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311737096.5A CN117907762A (en) | 2023-12-18 | 2023-12-18 | Ultrahigh frequency partial discharge detection method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311737096.5A CN117907762A (en) | 2023-12-18 | 2023-12-18 | Ultrahigh frequency partial discharge detection method and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117907762A true CN117907762A (en) | 2024-04-19 |
Family
ID=90682973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311737096.5A Pending CN117907762A (en) | 2023-12-18 | 2023-12-18 | Ultrahigh frequency partial discharge detection method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117907762A (en) |
-
2023
- 2023-12-18 CN CN202311737096.5A patent/CN117907762A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103119845B (en) | Method and apparatus for the fault in positioning and communicating network | |
| CN101644738B (en) | Local discharge detecting system of sulfur hexafluoride gas-insulating and fully-enclosed combined electric apparatus | |
| CN102331542B (en) | Transformer substation local discharging signal online monitoring and positioning method | |
| CN104601258B (en) | A kind of Vehicular communication system is with car multimachine mutual interference method of testing | |
| CN104062565B (en) | A kind of method utilizing intermodulation component detection microwave component micro discharge | |
| CN101650407B (en) | Sulfur hexafluoride gas insulation totally-enclosed combined electric partial discharge detection and positioning system | |
| CN113206697B (en) | Broadband radio frequency receiving and processing system device and self-checking method thereof | |
| CN201540349U (en) | Ultra-high frequency signal sensor for partial discharge detection | |
| CN109975772B (en) | Multi-system radar interference performance detection system | |
| CN109001600B (en) | Active full-frequency band online partial discharge detection method and system | |
| CN201540350U (en) | Hyper-high-frequency signal receiving device for detecting local discharge | |
| CN105897302A (en) | Wireless interference scanning method and wireless interference scanning device for adaptive frequency hopping | |
| CN110045256A (en) | A kind of SHF frequency range local discharge signal reception circuit | |
| CN106341195A (en) | Calibration system facing radio frequency front end and calibration method | |
| US11303366B2 (en) | Passive harmonic test system and method | |
| CN117907762A (en) | Ultrahigh frequency partial discharge detection method and device | |
| Mazzaro et al. | Hardware simulation of harmonic radar using a transverse electromagnetic cell | |
| CN104901753A (en) | Amplitude ratio and phase difference testing method and device for two homologous radio frequency signals | |
| Zhang et al. | A study on the memory effect of mixer | |
| CN211579979U (en) | Wi-Fi wireless test system and device | |
| Cheema et al. | Digital FMCW for ultrawideband spectrum sensing | |
| CN209070063U (en) | A kind of GIS equipment partial discharge detection device | |
| RU2726305C1 (en) | High-voltage insulators condition diagnostics device | |
| Keller | A new concept for a wideband FFT-Based EMI receiver | |
| CN108152622B (en) | Interference degree quantitative evaluation method for vehicle-mounted communication system in wave-absorbing darkroom |
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 |