Unsa ang mga Modo sa Automatic Reclosing ug Ilahang mga Katangian

Ang pag-reclose mahimong isulat sa tulo ka kategoriya: single-phase reclosing, three-phase reclosing, ug comprehensive reclosing.

Single-phase reclosing: Human sa pag-occur og single-phase fault sa line, gigamit ang single-phase reclosing. Kon ang reclosing naa sa permanenteng fault, gitripped ang tanang tulo ka phase ug walay uban pang attempt sa reclosing. Alang sa interphase faults, gitripped ang tanang tulo ka phase walay reclosing.

Three-phase reclosing: Bisag unsa ang klase sa fault, gitripped ang tanang tulo ka phase sumala sa three-phase reclosing. Kon ang reclosing naa sa permanenteng fault, gitripped ang tanang tulo ka phase usab.

Comprehensive reclosing: Alang sa single-phase faults, gigamit ang single-phase reclosing; alang sa interphase faults, gitripped ang tanang tulo ka phase sumala sa three-phase reclosing. Pagkahuman sa reclosing sa bisan unsang permanenteng fault, gitripped ang tanang tulo ka phase.

Single-Sided Power Source Three-Phase Single-Shot Reclosing

Karakteristik sa three-phase single-shot reclosing sa single-sided power source lines: 

• Walay lisod nga consideron sa power source synchronization check.

• Walay lisod nga distinguish sa klase sa fault o select sa faulted phases.

Operasyon proseso sa three-phase single-shot reclosing sa single-sided power source lines: 

• Reclosing initiation: Ang reclosing magsugod human sa circuit breaker tripping (non-manual). 

• Reclosing time delay: Human sa initiation, nag-delay ang timing elements bago mag-issue og closing pulse command. 

• Single closing pulse: Human sa pag-issue og closing pulse, nagsugod ang timing para sa complete reclosing group reset (15-25 seconds), preventing multiple reclosing attempts. 

• Blocking after manual tripping. 

• Post-reclosing accelerated protection tripping: Alang sa permanenteng faults, coordinated sa protection systems.

Prinsipyo sa setting sa minimum reclosing time: 

• Time required for feedback current from load motors to fault point after breaker tripping; time needed for fault arc extinction and insulation strength recovery of surrounding medium. 

• Time required for insulation strength recovery around breaker contacts after arc extinction, refilling of oil/gas in arc-quenching chamber, and operating mechanism recovery. 

• For reclosing via protective relay trip output, add circuit breaker tripping time. 

• (Note: This appears to be a duplicate of 3.3 in the original text)

Baton sa operational experience sa China's power systems, ang minimum reclosing time mao ang 0.3-0.4 seconds.

Dual-Sided Power Source Three-Phase Single-Shot Reclosing

Karakteristik sa three-phase single-shot reclosing sa dual-sided power source lines:

• Human sa fault tripping, adunay mga issues bahin sa whether ang duha ka power sources molabay pa o allowed ba ang non-synchronous reclosing. 

• Kinahanglan siguraduhon nga ang circuit breakers sa duha ka gilid mi-tripped bago ang reclosing.

Pangutana reclosing methods alang sa dual-sided power source transmission lines: 

• Fast reclosing: 

• • Circuit breakers capable of fast reclosing installed on both sides of the line. 

  • Full-line instantaneous protection installed on both sides, such as pilot protection. 

  • Inrush currents must remain within allowable limits for equipment and system impacts.

• Non-synchronous reclosing: Closing under out-of-step conditions. All power system components will experience inrush current impacts.

• Synchronism-check automatic reclosing: Closing only permitted after synchronism conditions are satisfied.

Requirements for synchronism-check reclosing:

• System structure must ensure no loss of synchronism.

• For double-circuit lines, check current flow on the other circuit.

• Must verify actual synchronism between both power sources before reclosing.

Optimal reclosing time for dual-sided power source three-phase reclosing:

The optimal reclosing time is calculated and set based on fault conditions most severely affecting system stability. This ensures minimal additional impact on the system when reclosing onto severe permanent faults. While not optimal for other fault types, it provides sub-optimal but acceptable performance, avoiding worst-case scenarios.