I. Overview
There may be quality defects and mechanical damage in the design, manufacture, transportation and installation of power equipment; Partial discharge may be caused by the presence of foreign matter, oxidation, loosening, pollution, aging and dampness during long-term operation in high voltage, strong electric field and harsh environment. Partial discharge (PD) is the main cause of damage to the insulation system of power equipment and power failure. In order to ensure the stable operation of power system and discover hidden dangers in time, it is necessary to carry out regular detection of PD.
Ultrasonic Detector of PD independently developed and produced by our company adopts high-precision ultrasonic sensor to collect characteristic sound waves emitted by partial discharge of 110kV and below power equipment. Through filtering,defects can be located and determined.
It is suitable for detecting the partial discharge of unenclosed equipment in the substation or on the transmission and distribution lines, such as switchgears, metal-enclosed switchgear,insulators, transformers, arresters, cable joints, fittings, etc.
II. Working Principle And Data Judgment
2.1 Testing principle
When partial discharge occurs in the insulation of power equipment, ultrasonic signals are generated. The ultrasonic signals are transmitted by the discharge power along the insulating medium, metal parts or air to the equipment shell, and spread to the surrounding air through the medium and gaps. The partial discharge of power equipment can be judged by coupling ultrasonic signal in air with ultrasonic sensor.
2.2 Judgment methods
(1)Based on the partial discharge characteristics of the sound heard in the headset, at the same time considering the duration,frequency of the sound.
(2)The amplitude and the waveform map in the detection process are used as auxiliary basis for judgment.
III. Instrument Composition
3.1 Introduction of group component
|
Name |
Picture |
Function/parameter |
|
Mainframe |
|
Collect and process ultrasonic signal, output audible sound and waveform map. |
|
Earphone |
|
High-performance soundproof headphones for listening to processed ultrasonic audio while protecting against external interference. |
|
USB memory |
|
Store detection data, audio, GPS information, etc |
|
Laser sight |
|
assist the instrument to locate the fault more accurately |
|
Charger |
|
Rated input voltage：AC100V～240V,250mA,50HZ Rated output voltage：DC5V 1500mA |
|
Portable mobile power supply |
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Double USB output, multiple protection, fast intelligent charging, prevent overcharge, overdischarge, high temperature, short circuit |
|
Analysis software |
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The analysis software can read and transfer the data collected on the site, and then organize and analyze, intelligent diagnosis, form a report, and assist users to make corresponding decisions. |
Parameter
|
Ultrasonic Detector |
Range |
0~60dBμV |
|
Resolution |
0.1dB |
|
|
Deviation |
±1dB |
|
|
Sensitivity |
-70dB(When the distance is not less than 10cm, the maximum discharge power of more than 100pC can be detected) |
|
|
Center frequency |
40kHz |
|
|
Effective distance
|
Voltage class |
Detection distance |
|
10kV |
15m |
|
|
35kV |
35m |
|
|
110kV |
51m |
|
|
Information output |
display screen |
3.5 "color TFT touch screen with a resolution of 320×240 |
|
Earphone |
3.5mm jack with standard 16Ω noise-cancelling earphones |
|
|
USB |
Rated capacity 16G |
|
|
CPU |
Sampling speed: 10k/s; Sampling accuracy: 16 bit AD |
|
|
GPS |
Using passive ceramic antenna, can directly receive GPS satellite signals; Equipped with IPX interface, extensible active antenna, suitable for vehicle use. Up to 50 parallel channels, supporting fast star search; Cold start only 27s minimum. |
|
|
Display mode |
Real-time mode, Transient mode, peak hold |
|
|
Storage format |
Data:DAT;audio:WAV; |
|
|
Recording |
can record audio with a sampling rate of 48kHz and the recording time is adjustable. The default recording time is 10s |
|
|
Temperature |
-10℃～50℃ ±2℃ |
|
|
Humidity |
≤90%RH ±4.5%RH |
|
|
Power supply |
Lithium battery with DC3.7V voltage and 8000mAH capacity; sustainable power supply for 8 hours of full load operation, 12 hours of normal operation; 20 hours of low power operation; Power consumption in the off state is 40uA |
|
|
Packing Size |
353 x 190 x 90(mm) |
|
|
Weight |
About 0.75kg |
|