Rêbaza Veşta û Pêwistkirina Kapanên Dîjîna Elektrîkî

Kavanîna û Pêşkeftina Piranên Nergirtina Elektrîk

Piranên nergirtina elektrîk piranên kompenzasyonê statîk neyîn bûyîn an reaktîf yên li ser pargrîtên elektrîk da ku werin bikar anîn ji bo hewalatkirina nergirtina reaktîf û bêtir bike çemkirdina faktora nergirt. Bi hatinek kirina kompenzasyonê reaktîf ya herêmî, wan dikarin dîmendekîna vêran bejne, zêdeberên nergirt û kerkûbên nîsgayîn bixebite û li ser bêtir bike sedema nergirt û bikar bînên cihazan.

Daxwaza meya taybetandî yên operasyona û pêşkeftina piranên nergirtina elektrîk li jêr hatiye navkirin.

1. Parastina Piranên Nergirtina Elektrîk

(1) Divê xeyala parastina wekheviyê li ser banka piranên nergirt bikin. Wan dikarin pêvajoya parastina taraz û diferansiyel an parastina relaya overcurrent instantaneous bûn. Ji bo piranên nergirtina elektrîk bi derdîna 3.15 kV û piçey, heqetan divê di her pirê de füzyon ek birin. Derdîna füzyonê divê bi temsiliyê füzyon û dîmendekîna energîzekirina sereka hilbijêrin, mîna 1.5 her dem derdîna piranê, bi tenê ku bigire warên tanka û nafra nebe.

(2) Li ser beriya meya, ji kerema xwe divê xeyala parastina bêtir bikin:

• Ger çendîna demê voltaj bergekir û dest pê deqe, divê xeyal bike ku voltaj ê li vir 1.1 her dem derdîna namekirî nebe.

• Bikar bînin ciwanên automatîk u hêsan da ku li ser overcurrent parast bike, li vir 1.3 her dem derdîna namekirî nebe.

• Geriya ku piranên nergirt di raste û şertên havara de girin, divê ciwanên surge arresters wekhevî li ser atmosferik overvoltages parast bikin.

• Li sisteman nergirtina malpera ku dîmendekîna short-circuit bi 20 A vebar e û ciwanên parastina standard û füzyonê tune ye ku guherandina faultên ground reliable nebike, divê parastina faulta single-phase ground bikin.

(3) Hêlbijarkirina rastîn a xeyalan parastina niha yekemîn e bi kar û pêşkeftina piranên nergirtina elektrîk. Li gor bilî metoda bikaranîn, sistemê parastina divê şertên meya hatiye bide:

• Destûrîna bas bi rêza ku li ser faultên interna ya her pir û çarabekirina elementên yekane hatine opereyekirina reliable bide.

• Tiştina ku piranên faulted li ser seleksiyonê rakirin, an li ser ragihandinê ra piranên damaged beseke.

• Nabe ku li ser switching operations an faultên sisteman wek faultên ground trippingên false bide.

• Bas bi rêza ku instale, tevahî, test, û pêşkeft bike.

• Dîmendekîna nergirt û costa operatingê ya bêher.

(4) Divê autoreclosing li ser banka piranên nergirtina elektrîk nasaz bikin. Di wê yer de, divê device û release trip undervoltage bikar bînin. Ekuwa ku piranên nergirt dibêjin dema discharge. Ger reclose li ser demeke tripping reke, qalankirina residual û voltage û polaritiya sererast bide, li vir inrush currents û bi abdar bûne, ku dikarin tanka bulging, nafra, an explosion bide.

2. Energizing û De-energizing Piranên Nergirtina Elektrîk

(1) Piştî ku banka piranên nergirt ê energize bikin, bikar bînin megohmmeter û check discharge circuit bikin.

(2) Li ser switching banka piranên nergirt, li jêr ê amûrên bêtir bexwestin:

• Banka piranên nergirt na bikin ji grid ê ji roja ku voltaj bus vir 1.1 her dem derdîna namekirî nebe.

• Piştî ku ji grid ê disconnect bikin, banka piranên nergirt ê ji roja 1 minute energize bike, herî li ser applications û automatic repeated switching.

• Ciwanên circuit breaker û switching ê tune ye ku overvoltages dangerous nebigirin. Derdîna rated current ê circuit breaker ê li vir 1.3 her dem derdîna banka piranên nergirtina namekirî nebe.

3. Discharge Piranên Nergirtina Elektrîk

(1) Piştî ku ji grid ê disconnect bikin, piranên nergirt ê automatically discharge bikin. Voltaj terminal ê li ser çendîna demê li ser bergekir û, li gor derdîna rated voltage, li vir 65 V nebe 30 seconds li ser disconnect bikin.

(2) Ji bo bêtir bike safe, divê devices û automatic discharge saz bikin li ser load side û circuit breaker û directly parallel bi pir (switches, isolators, û fuses ê tune ye ku li ser series nebigirin). Banka piranên nergirt ê ku devices û non-dedicated discharge û voltage transformers (ji bo piranên nergirtina high-voltage) û incandescent lamps (ji bo piranên nergirtina low-voltage) û motors ê tune ye ku additional discharge devices nebigirin. Ji bo lampên, service life ê bi zêdekirina numera lampên û series bigere.

(3)  Piştî ku ji conductive parts ê disconnected capacitor ê touch bikin, heta automatic discharge ê çêbikin, divê metal rod û grounded, insulated bikar bînin û terminals ê capacitor ê short-circuit bikin manual discharge.

4. Maintenance û Care During Operation

(1) Banka piranên nergirt ê monitor bikin li ser personnel trained, û records ê operation ê nusname bikin.

(2) Inspectionên visual ê daily bikin li ser regulations ê operating banka piranên nergirt. Ger tanka bulging ê bînin, unit ê immediately out of service bike prevent failure.

(3) Phase current ê banka piranên nergirt ê monitor bikin ciwanên ammeters.

(4) Piranên nergirt na bikin energize ji roja temperature ambient vir −40 °C. Li ser operation, average temperature ê li vir +40 °C 1 hour, +30 °C 2 hours, û +20 °C annually nebe. Ji roja limits ê exceed bikin, artificial cooling (e.g., fans) bikin use û û banka piranên nergirt ê disconnect bikin ji grid.

(5) Temperature checks ê installation site û hottest spot ê casing ê capacitor ê perform bikin mercury thermometers û equivalent, û records ê keep (especially during summer).

(6) Operating voltage ê li vir 1.1 her dem rated voltage nebe; operating current ê li vir 1.3 her dem rated current nebe.

(7) Connecting capacitors ê raise system voltage, especially under light load. Ji roja cases ê, part û all ê banka capacitor ê disconnect bikin.

(8) Bushings û support insulators ê clean, undamaged, û free of discharge marks. Casing ê capacitor ê clean, undeformed, û leak-free. No dust û debris ê accumulate on capacitor û its support frame.

(9) All connections ê capacitor circuit (busbars, grounding wires, circuit breakers, fuses, switches, etc.) ê inspect bikin for reliability. Even a loose screw û poor contact ê lead to premature capacitor failure û system-wide incidents.

(10) Ji roba dielectric withstand test ê required after a period ê operation, it must be conducted at the specified test voltage.

(11) Inspection ê capacitance values û fuses ê performed at least once per month. The loss tangent (tanδ) ê capacitors ê measured 2–3 times per year under rated or near-rated voltage to assess insulation condition.

(12) Ji roba capacitor bank ê trips due to relay operation, it must not be re-energized until the cause is identified.

(13) Ji roba oil leakage ê found during operation û transport, it may be repaired by brazing with tin-lead solder.

5. Switching (Isolation) Operation Precautions

(1) Under normal conditions, during complete substation shutdown, the capacitor bank circuit breaker should be opened first, followed by the outgoing line breakers. During re-energization, the sequence should be reversed.

(2) In the event of a complete power outage, the capacitor bank circuit breaker must be opened.

(3) After a capacitor bank trips, forced re-energization is prohibited. If a protective fuse blows, the fuse must not be replaced and re-energized until the cause is determined.

(4) Capacitors must not be energized while charged. After disconnection, re-closing must be delayed for at least 3 minutes.

6. Fault Handling During Operation

(1) In case of oil spraying, explosion, or fire, immediately disconnect the power supply and extinguish the fire using sand or a dry-type fire extinguisher. Such incidents are typically caused by internal/external overvoltages or severe internal faults. To prevent recurrence, ensure fuse ratings are correct, avoid forced re-energization after tripping, and do not use auto-reclosing.

(2) If the circuit breaker trips but the branch fuse remains intact, discharge the capacitor for 3 minutes, then inspect the breaker, current transformer, power cable, and external condition of the capacitor. If no abnormalities are found, the fault may be due to external disturbances or voltage fluctuations. After confirmation, a test re-energization may be attempted. Otherwise, conduct a full energized test of the protection system. If the cause remains unidentified, dismantle the bank and test each capacitor individually. Do not attempt re-energization until the cause is found.

(3) When a fuse blows, report to the duty dispatcher and obtain approval before opening the capacitor circuit breaker. After de-energizing and discharging, perform an external inspection (e.g., bushing flashover, casing deformation, oil leakage, grounding faults). Then measure inter-terminal and ground insulation resistance with a megohmmeter. If no fault is detected, replace the fuse and resume operation. If the fuse blows again upon re-energization, isolate the faulty capacitor and restore service to the remainder.

7. Safety Precautions When Handling Faulty Capacitors

Before handling a faulty capacitor, disconnect its circuit breaker, open the disconnect switches on both sides, and discharge the bank through the discharge resistor (e.g., discharge transformer or VT). Due to possible residual charge, a manual discharge must still be performed. First, securely connect the grounding end of the grounding rod, then repeatedly discharge the capacitor terminals until no sparks or sounds occur. Finally, secure the ground connection.

Faulty capacitors may have poor internal connections, open circuits, or blown fuses, leaving residual charge. Therefore, maintenance personnel must wear insulating gloves and short-circuit the two terminals of the faulty capacitor with a shorting wire before touching it.

For capacitor banks with double-star connections, the neutral line, and for series-connected capacitor strings, individual discharge must also be performed.

Among substation equipment, power capacitors are relatively vulnerable due to weaker insulation, higher internal heat generation, poor heat dissipation, higher internal failure rates, and combustible internal materials, making them prone to fire. Therefore, favorable low-temperature and well-ventilated operating conditions should be provided whenever possible.

8. Repair of Power Capacitors

(1) The following faults may be repaired on-site:

• Oil leakage from the casing can be repaired by soldering with tin-lead alloy.

• Oil leakage at bushing welds can also be repaired by soldering, but care must be taken to avoid excessive heat that could damage the silver plating.

(2) Failures such as ground insulation breakdown, significantly increased loss tangent, severe casing bulging, or open circuits require repair at specialized capacitor service facilities equipped with proper tools and testing equipment.