Vipi ni sababu za matatizo ya current transformer na hatua za kusaidia kuhusu matatizo?

Kama mteja wa kifaa wa huduma za umuhimu wa kwanza, ninahusisha na transformers ya current (CTs) kila siku. CTs hupanua maguta muhimu ya primary current hadi maguta madogo ya secondary current kwa ajili ya uzalishaji/ujumbe wa substation/line na uchanganuzi, kufanya kazi kwa muda mrefu. Hata hivyo, wanakutana na matatizo kutoka nje (maelezo yasiyofanikiwa, ukoloni wazi, ndrl.) na ndani (matatizo ya insulation). Matatizo haya, kama secondary open-circuits au insulation breakdown, huathiri ufanisi wa uchanganuzi, uendeshaji wa protection, na ustawi wa grid. Chini, ninashiriki maoni kutokana na tajriba.

1. Mfumo wa CT (Mtazamo wa Huduma)

CT una windings ya primary/secondary, core, na insulation (oil-immersed, SF6, solid). Primary winding inawezekana kwenye circuit, secondary unahusiana na vifaa/vyumba. Muhimu: Viwindings vya primary vigawa zaidi, viwindings vya secondary vibadilishane, na kufanya kazi kama short-circuit normal operation. Muhimu: Usione secondary circuit; ground it reliably (nimeona arc flashes ngumu kutokana na circuits wazi).

2. Kazi & Sura (Tajriba)

CTs hupunguza maguta makubwa kwa ajili ya uzalishaji/uchanganuzi salama kupitia electromagnetic induction, kukutana na high voltage. Wakati wa calibration, ninachukua ratios ya primary-secondary current ili kuthibitisha CTs.

3. Classification ya Performance
(1) Optical CTs (OTA)

Imebunywa kulingana na Faraday magneto-optical effect, inatumika katika grid tests. Sensitive to temperature lakini nzuri kwa magnetic fields ngumu.

(2) Low-Power CTs

Na microcrystalline alloy cores, wanatoa mazingira linear wide, low losses, na ufanisi wa juu kwa maguta makubwa—ideal kwa uchanganuzi wa kiwango cha kimataifa.

(3) Air-Core CTs

Hawana iron core, kurejesha magnetic saturation. Popular katika relay protection kwa anti-interference ngumu, inapatikana kwa mazingira magumu.

4. Sababu za Matatizo (Tajriba)
(1) Thermal Breakdown ya Insulation

CTs wa high-voltage hutoa moto/losses dielectric. Insulation defective (mfano, ukoloni usio sawa) hutoa moto zaidi na thermal breakdown—common katika vifaa vya zamani.

(2) Partial Discharge

Capacitance ya normal CT hutolewa sawa, lakini manufacturing/structure isiyofanikiwa (mfano, screens zisizosawa) hutoa magnetic fields mikubwa mahali pa moja. Partial discharges ambayo hazitoshulwa huathiri capacitors.

(3) Secondary Load Kubwa Zaidi

Maegesho mengi katika 220 kV systems hutoa secondary voltage/current zaidi, kuathiri errors. Faults zinaweza kusaturate cores, kuburudisha relays. Secondary circuits wazi (mfano, wires wazi) hutoa voltage kubwa—risky!

5. Jibu la Matatizo
(1) Fuata Sheria za Uendeshaji

• Wiring: Series-connect circuits, windings, na vifaa vizuri; tumia configurations sahihi (single-phase, star).

• Error Compensation: Ongeza windings/cores kuboresha errors kupitia capacitance/inductance.

• Calibration: Fanya demagnetization/polarity tests baada ya installation/maintenance.

(2) Handling ya Dharura (Safety First)

• Power Off: Toa power mara moja kwa safety.

• Angalia Secondary Circuit: Tafuta circuits wazi, minimize primary current, tumia vifaa vya insulation, na fuata diagrams.

Kwa secondary open circuits:

• Assess Impact: Identify affected circuits, report to dispatch.

• Reduce Load/Isolate: Transfer loads and de-energize if damaged.

• Short-Circuit Secondary: Use approved materials; sparks mean downstream faults, no sparks mean upstream issues.

(3) Teknolojia za Detection

• Insulation Testing: Measure dielectric loss, capacitance kutoa defects—nzuri kwa aging assessment.

• Infrared Thermography: My key tool! Detects loose connections/thermal issues quickly.

Conclusion

CTs ni muhimu kwa ustawi wa grid. Kuwa na maarifa kwa mfumo, sura, na jibu la matatizo huaminisha ustawi. Kutumia guidelines, using detection tools, na kutenda katika dharura hupunguza failures—kuaminisha grid salama.