Gabatarwa a Tushen Daidaitaccen Zabi na Tekunolojin Da Ba A Farko Don Yankin Riga Masu Kwalba
Wanda jin daidaitun da kungiyar noma, yadda ake fito tashar RMU (Ring Main Unit) mai karamin hanyoyi ta zama da ya fi shafi. Yadda ake yi aiki a kan wannan tashar ya haɗa da ƙarin al'amuran bayanai na gajeruwar noma. Idan ake faruwa, abubuwan da suka faru sun hada da: karfin da suka faruwa a kan gasar da kuma abincin da suka faruwa, kuma rarrabban noma. Abubuwan da ba suka faruwa ba sun hada da rarrabban noma a kan mutane da kuma rarrabban rayuwa, aikatau rarrabban gwamnati.
A lokacin, abubuwan da ba da suka faruwa a kan hanyoyin da ake amfani da su don yanayin tashar RMU da kuma yadda abubuwan da ba da suka faruwa ba suka faruwa a kan tashar da ake amfani da su don aiki, sun hada da ƙarin al'amuran bayanai na gajeruwar noma. Yanayin PD (Partial Discharge) wani hanyoyi ne da ke da muhimmanci don inganta hanyoyin da ake amfani da su don aiki da kuma tattauna abubuwan da ba da suka faruwa ba. Wannan hanyoyi ya haɗa da bayanai na muhimmanci don inganta hanyoyin da ake amfani da su don aiki a cikin tashar da ake amfani da su don aiki, kuma ya haɗa da ƙarin al'amuran bayanai na gajeruwar noma. A cikin tashar da ake amfani da su don aiki, idan abubuwan da ba da suka faruwa ba suka faruwa, ba suka faruwa saboda sautin kungiya kawai, kuma za a iya faruwa saboda sautin kudanci, karamin harkar kudanci, ko karamin harkar kudanci da kungiyar kudanci, kuma ya haɗa da ƙarin al'amuran bayanai na gajeruwar noma. Don in taimaka masu aiki da kuma in taimaka masu aiki don inganta hanyoyin da ake amfani da su don aiki, ake amfani da hukumomin da suka faruwa daga fadin da na 'yan sanda da kuma fadin da na 'yan dunia, a nan State Grid Corporation Production Substation Notice [2011] No. 11 "Notice on Issuing the 'Technical Specification for Live Testing of Power Equipment (Trial)'", wannan bincike ya haɗa da yanayin PD (Partial Discharge) don tashar RMU.
II. Hanyoyin Yanayin Partial Discharge (PD) don Tashar Ring Main Units (RMU)
1. Tsarin PD Energy
Partial discharge wani abu ne da ke da muhimmanci don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyi ya haɗa da tsari na charge transfer da kuma power dissipation, kuma ya haɗa da electromagnetic radiation, ultrasonic waves, light, heat, da kuma abubuwan da suka faruwa. Hanyoyin da ake amfani da su don yanayin waɗannan abubuwa sun hada da electrical detection, acoustic detection, optical detection, da kuma chemical detection. Daga cikin waɗannan, hanyoyin electrical da acoustic suna da muhimmanci, amma har zuwa da muhimmiyar nasara, domin hanyoyin da suka faruwa a kan samun noise interference a cikin samun samun aiki. In kawo nasara da muhimmanci don inganta hanyoyin da ake amfani da su don aiki.
Abubuwan da ake samu:
- Electrical: (TEV, UHF, HFCT sensors)
- Acoustic: (Ultrasonic sensors)
- Optical: (Visible through viewing windows in specific locations during discharge)
- Thermal: (Infrared, though detection effectiveness is limited by the RMU's fully enclosed structure)
- Chemical/Gas: (Ozone smell, etc.)
2. Teknologi
Yana da hanyoyin da suka faruwa a kan yanayin PD (Partial Discharge) don tashar da ake amfani da su don aiki, suna da muhimmanci don inganta hanyoyin da ake amfani da su don aiki. Waɗannan hanyoyin suna da muhimmanci don inganta hanyoyin da ake amfani da su don aiki, suna da muhimmanci don inganta hanyoyin da ake amfani da su don aiki, kuma suna da muhimmanci don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin direct method ce, wanda ake amfani da ita don inganta hanyoyin da ake amfani da su don aiki. Wannan hanyoyin indirect method ce, wanda ake amfani da ita......
1) Ultrasonic Detection for Solid-Insulated RMUs
By receiving ultrasonic signals transmitted through the air and measuring the acoustic pressure of the PD signal, the discharge intensity can be inferred. During ultrasonic testing, the sensor should be scanned along the seams/gaps on the switchgear surface. Reference diagrams provide guidance on typical detection locations.
2) Principle of Transient Earth Voltage (TEV) Detection
When PD occurs inside a high-voltage switchgear cabinet, an extremely short-duration pulsed current flows along the discharge channel, exciting transient electromagnetic waves. The rapidity of the discharge process results in a steep current pulse with strong high-frequency electromagnetic radiation capability. This radiation can propagate through openings in the metal enclosure, such as sealing gaskets or gaps around insulation. When these high-frequency electromagnetic waves propagate outside the cabinet, they induce a transient voltage on the outer surface relative to earth ground. This transient voltage on the earth (TEV) ranges from millivolts to volts with a rise time of a few nanoseconds. A dedicated TEV sensor placed on the outside of the cabinet can detect this signal non-invasively.
Main TEV Detection Locations (on cabinet walls opposite):
- Busbars (connections, wall bushings, support insulators)
- Circuit Breakers
- Current Transformers (CT)
- Voltage Transformers (PT)
- Cable Terminations
These components are typically located on the middle and lower sections of the front panel, the upper, middle, and lower sections of the rear panel, and the upper, middle, and lower sections of the side panels.
III. PD Localization and Phase Identification
Once sensor signals are confirmed to originate from within the equipment, Time Difference Of Arrival (TDOA) localization is used for further positional analysis. Two sensors are placed on the equipment surface; the time difference between their received signals (t2 - t1) is analyzed to determine the PD location, usually within a 1-meter range of the source.
1. Time Difference Method:
Assume the PD source is distance X from sensor 1, electromagnetic wave speed = c (speed of light), and the time difference t2 - t1 is measured via oscilloscope.
X = (t2 - t1) * c / 2
Using this formula and a tape measure, position X can be determined.
2. Plane Bisector Method:
- Move the two sensors in space until the PD signal arrival time is identical at both. This locates the discharge point on the perpendicular bisecting plane between the two sensors (Locating the Plane).
- Move the sensors within this bisecting plane until the arrival time is identical again. This locates the discharge point on the perpendicular bisecting line within that plane (Locating the Line).
- Move the sensors along this bisecting line until the arrival time is identical once more. This pinpoints the discharge location (Locating the Point).
To identify the specific phase experiencing PD, the HFCT method is used to detect signals on the ground leads (or body) of the adjacent three-phase outgoing cables. The current signal from the defective phase exhibits a larger amplitude and opposite polarity compared to the signals on the other two phases, allowing straightforward identification of the faulty phase.
