Study of backup power supply adaptive to Distribution Line Non-Communication Protection

This paper presents a new practical backup power supply connection scheme for Distribution Line Non-Communication Protection (DNCP). Simulation tests have been conducted using the Alternate Transient Program (ATP) with respect to a typical single circuit breaker multi-section system. Additional theoretical analysis has also been done in the condition of unsymmetrical fault on L3 to identify the variation of fault phase current. The results prove that the new scheme is able to not only recover the power supply of loads on healthy lines automatically, but also create disturbances in favour of Accelerated Over Current (AOC) criterion.