In a transmission system, auto reclosing is a protection scheme that automatically re-closes a circuit breaker after it has been tripped due to a fault. Auto-reclosing is to restore power to the transmission line as quickly as possible after a spot has been cleared. This helps minimise the power supply disruption and reduce the impact on customers.
Auto-reclosing is typically used with other protection schemes, such as fault detection and location, to ensure that the fault is cleared before the circuit breaker is re-closed. The auto-reclosing process is typically controlled by a protective relay, which monitors the transmission line and sends a signal to the circuit breaker to close when it is safe.
There are several different types of auto-reclosing schemes, including single-shot, multishot, and selective auto-reclosing. Single-shot auto-reclosing is the most common type and involves closing the circuit breaker once after a fault is cleared. Multishot auto-reclosing consists in closing the circuit breaker multiple times to clear the fault. Selective auto-reclosing is a more advanced technique that involves completing only the portion of the transmission line that is downstream from the fault, leaving the rest of the line open.Overall, auto-reclosing is an important protection scheme in transmission systems, as it helps to restore power quickly after a fault and minimize the impact on customers.
Advantages of Auto Reclosing Scheme
There are several advantages to using auto-reclosing schemes in a transmission system:
- Quick restoration of power: Auto-reclosing allows the circuit breaker to be re-closed as soon as the fault is cleared, which helps to restore power to the transmission line quickly. This minimizes the disruption to the power supply and reduces the impact on customers.
- Improved reliability: By quickly restoring power after a fault, auto-reclosing helps to improve the overall reliability of the transmission system.
- Reduced maintenance costs: Auto-reclosing can reduce the need for maintenance on the transmission line, as it reduces the number of times the circuit breaker needs to be manually opened and closed.
- Increased efficiency: Auto-reclosing can increase the efficiency of the transmission system, as it allows power to be restored quickly and reduces the need for manual intervention.
- Enhanced safety: Auto-reclosing can enhance safety by automatically re-closing the circuit breaker after a fault has been cleared, reducing the risk of human error and ensuring that the transmission line is only re-closed when it is safe to do so.
This is precisely what an auto-recloser or auto-closing method performs. Eighty percent of problems in an overhead line of transmission are temporary, while twelve percent are only partially permanent. If the fault also isn’t cleared on the first try, the auto-reclosing method will retry closure the circuit twice or three times before giving up. If the problem persists, the circuit breaker will be opened permanently under this plan. The auto-reclosing system may be delayed for a set amount of time to let the semi-permanent fault clear out of the circuit.