Iyaliwa da darasi na ƙarfi na kabelon hanyoyi

1. Bayanin Testin Daidaitaccen Tsarin Kable na Tashar Jirgin Lafiya

Testin daidaitaccen tsarin kable na tashar jirgin lafiya yana nufin bayanai masu inganci, tare da amfani da abubuwa masu ilimi, wajen cikakken paramatar addinin kamar riyarsa, induktansi, kapasitansi, da konduktansi kablar a lokacin da kable ya faru ko a kan wasu baya mai gudummawa. Gagga ta shine maimakon bayanai daban-daban wajen bayyana tsarin addini na kable, wanda ke jagoranci tsari mai muhimmanci wadanda ke bayyana paramatar masu inganci don cikakken bayanai tsarin karamin lada, girman babban hanyoyi, bayanan siyasa na rawa, da kuma tattaunawa halayyar kable.

Ma'anarta a fili bi ne biyu: kima, fuskantar farko-farko daga ma'adanai uku da ma'adar da suka samu, don ba a gane mutuwa ko matsaloli na hanyoyi saboda fitaccen paramata; kuma, haɗa kan "takardun bayanai daban-daban" na kable, wanda ke bayyana nasara don inganta halayyan sahihi (kamar zama-zamanin insuladi ko haɗa shiga mai mahimmanci). Daga DL/T 596 "Tashar Addinin Amfani da Abubuwan Addinin Karamin Lada" da GB 50217 "Tashar Inganci Don Bincike Masu Inganci na Kable," yana buƙaci a yi kowane testin daidaitaccen tsari don kabiluwar 220 kV da kusa, inda 110 kV da kusa za a iya yi ne daga ƙarfafa na muhimmancin hanyoyi.

2. Tashar Mafi Yawan Testin Daidaitaccen Tsarin Kable na Tashar Jirgin Lafiya

2.1 Tashar Kirkiro

2.1.1 Ƙara Magangan Taushen Fanni da Tafakin Aiki
Yana buƙaci a samun magangan daban-daban na bayanai na kable, sama da tasiri (misali, 220 kV, 500 kV), modelin kable (misali, YJV22-220 kV-1×2500 mm²), tsarin amfani (shigo-shigo, tunna, cable tray), tsari (daidai zuwa 0.1 km), kayan adadin tashar (tambaya ko alwansa), tsarin insuladi (XLPE, paper mai shiga tattalin), da tsarin shield metal (copper tape, copper wire), da kuma tsarin haɗa (haɗa shiga, cross-bonded grounding). Yana buƙaci a yi tafaki a kan takarda mai gudummawa (mai yawa wani birnin kabilu) da takarda mai bincike (birnin kabilu mai gaba), tsarin haɗa, kyaukyauwa daga wurare addinin da suke da shiga (≥1.5 marubucin kyaukyauwa na tsari na test), da kuma amfani da voltmetar electrostatic don ƙara volts mai shiga (wanda ya iya kasance tens of volts a wurare kabiluwar da suke da shiga, don hana matukar karami).

2.1.2 Tashar Rike da Zabinta Abubuwan Ilimi

Daga "Bayanai Don Tashar Paramatar Kable," yana buƙaci a yi rike mai bayanai da ke ƙarƙashin abubuwan ilimi (paramatar positive-sequence, zero-sequence capacitance, etc.), modelon abubuwan ilimi, tsarin kula, da tashar hana matukar. Abubuwan ilimi mai muhimmanci sun hada da:

• Abin daidaitaccen tsari (accuracy class 0.2, frequency range 45–65 Hz, output current ≥10 A);

• Regulator voltage ta ɗaya (capacity ≥5 kVA, adjustable range 0–400 V);

• Transformer mai haɗa (1:1 ratio don hana fitaccen grid);

• Abubuwan ilimi mai bincike: thermometer/hygrometer (temperature da humidity ya zama a ƙara don tashar temperature correction), discharge rod (25 kV class, discharge time ≥5 min), shorting wires (cross-sectional area ≥25 mm² copper cable, length customized on-site), and insulating pole (3 m, insulation resistance ≥1000 MΩ).

2.1.3 Tashar Hana Matukar

Yana buƙaci a ƙara takarda mai hana matukar da alamomin "High Voltage Danger." Birnin kabilu mai gudummawa da birnin mai bincike suna buƙaci a amfani da walkie-talkies (communication range ≥1 km) da bututu mai hana matukar. Dukkan mutanen ilimi suna buƙaci a ƙara gloves mai insuladi (35 kV class), shoes mai insuladi (breakdown voltage ≥15 kV), da kuma safety harnesses a lokacin da ake yi aiki a wurare. Kabilu a gaba ya buƙaci a haɗa shiga daga abubuwan ilimi da suke da shiga don hana back-feeding.

2.2 Tashar Ƙara Testin a Takarda

2.2.1Kula da Tashar Phase Verification
Misali, a lokacin da ake yi testin paramatar positive-sequence, tashar kula ce:
(1) Short-circuit and ground the three-phase conductors (A, B, C) at the far end; ground the metallic shield at one end only (for cross-bonded systems, disconnect the bonding links in the cross-bonding box and test each section separately);
(2) Apply AC voltage (typically 380 V) to phase A at the main test end via a voltage regulator and isolation transformer; leave phases B and C open; connect the voltage and current sampling leads of the line parameter tester.
Phase verification: Use a multimeter to measure the voltage phase of each phase to ensure correct same-name phase connections and avoid measurement errors due to incorrect phase sequence.

2.2.2Tashar Ƙara Testin Paramatar
Positive-sequence resistance (R1) and reactance (X1): Apply test current (typically 5–10 A) to phase A, measure the magnitude and phase angle difference between voltage and current, and calculate using the formulas R1 = U/I·cosϕ and X1 = U/I·sinϕ. Repeat the test three times and take the average value, with at least a 1-minute interval between tests to prevent conductor heating from affecting resistance values.
Zero-sequence capacitance (C0): Short-circuit and connect phases A, B, and C to the high-voltage terminal of the tester, ground the metallic shield, apply 100 V, and measure capacitance using the Schering bridge principle. Linearity must be verified at different voltage levels (50 V, 100 V, 200 V), with deviations ≤2%.
Insulation resistance (Rins): Use a 2500 V megohmmeter to measure insulation resistance between conductor and shield. Record the reading after 1 minute of applied voltage and simultaneously record ambient temperature. Convert to the 20°C reference value using the formula R20 = Rt × 10^(0.004(t−20)) (where t is the measured temperature).

2.2.3Tashar Ƙara Bayanai da Tashar Daidaitaccen
Immediately after completing each parameter test, record the instrument reading, ambient temperature and humidity, test time, and any anomalies (e.g., voltage fluctuations, unusual noises). Data validity criteria include:

• Relative deviation of three repeated measurements of the same parameter ≤5%;

• Deviation of positive-sequence impedance from design value ≤10% (accounting for installation length error);

• Insulation resistance, after temperature correction, should be ≥1000 MΩ·km (standard for XLPE cables).

2.3 Tashar Ƙarfin Testin

2.3.1 Safe Discharge and Wiring Removal
After testing, first disconnect the power supply to the voltage regulator. Then, use a discharge rod to perform "multiple discharges" on the cable conductor and shield (each discharge lasting ≥1 minute, with a 30-second interval). Only after confirming the residual voltage is ≤50 V should the shorting wires and test leads be removed. For cross-bonded systems, reconnect the bonding links in the cross-bonding box and measure continuity to ensure proper connection.

2.3.2 Data Correction and Report Preparation
According to GB/T 3048.4 "Methods for Electrical Testing of Electric Wires and Cables," measured parameters must be corrected for temperature and frequency:
Resistance temperature correction:
For copper conductors: R₂₀ = Rₜ / [1 + α(t − 20)] (where α = 0.00393/°C);
Capacitance frequency correction:
When the test frequency deviates from 50 Hz, correct using: C₅₀ = Cf × (1 + 0.002∣f − 50∣).
The test report must include the testing standard (e.g., DL/T 475), instrument calibration certificate number, a parameter comparison table (design values vs. measured values), and a conclusive assessment (e.g., "Pass", "Retest Recommended").