PMU-assisted overcurrent protection for distribution feeders employing Solid State Transformers

Solid State Transformer (SST) has recently emerged as an approach to facilitate the integration of Distributed Energy Resources (DERs) at the distribution system level. However, SSTs impact the operation and coordination of protection relays as they will contribute to the fault current during a fault. This paper shows that the impact of SSTs on the overcurrent protection relays can be considerable. The paper proposes an enhancement to the traditional overcurrent scheme by exploiting embedded PMU functionality in SSTs and in feeder protective relays. Performance of the proposed scheme has been assessed through the use of hardware-in-the-loop simulation on a sample distribution feeder.