Research On Fault Isolation Scheme In Feeder Automation

On the study of comparing the existing feeder automation technology, a new automated fault isolation scheme based on recloser-recloser principle is put forward. The scheme improves the resistor of contactor in breaker or uses the IGBT device to design the circuit for increasing the rapid breaking capacity of the circuit breaker to meet with the requirements of 0.1 second for overcurrent protection. The paper proposes a new theory-the 0.1 second short delay-fast tripping protection that can solve the problem of breaker tripping overgrade which is caused by discriminating the protective reference value in distribution networks. The bidirectional protective reference value is applied in the ring power net to meet with the dynamic adjustment for the value. In the paper, a new method is presented that can isolate the fault of single-phase grounding by detecting the steep rise of zero sequence voltage. The software system is compiled and tested by experiments. The scheme can isolate the failure at any point in the feeder automation by one reclosing operation so that we can greatly improve the ability of rapid fault isolation and restoration of non-fault section of the power supply in the local distribution network.