Reliable protection of distribution systems is becoming increasingly challenging with growing distributed energy resources (DERs) and microgrids. Existing adaptive overcurrent relaying (AOCR) schemes are vulnerable to DER ride-through and generally focus on only grid or islanded modes. This paper presents a dynamic AOCR scheme independent of external controllers to estimate relay pickup which ensures significantly less communication overhead. Existing and emerging challenges for the state-of-the-art are discussed and resolved using the proposed scheme. The reliability is tested using transient system models in Simulink for all combinations of state and fault types/impedances in a 15-bus distribution system.

Energy Storage System (ESS), with its fast ramping and bi-direction power flow capabilities, is playing a more vital role in the electric market. However, it still stands on the farther end of economic viability. As a result, a good estimate of battery service life, and therefore revenue, is necessary before the investment is made in any given application. In this paper, a set of improved degradation models are propose to estimate the useful life of an ESS when subjected to daily duty cycles (4-sec resolution). The models are validated and tuned for the target Li-Nickel Cobalt Aluminum Oxide (NCA) batteries. Time to End of Life (EOL) is estimated for batteries of different sizes to provide ancillary services and/or energy services in electric market, given different end-of-cycle state of charge. Finally, the strategies which can be used to size the battery for maximizing time to EOL are discussed.

Considerations for electrifying school buses are presented with an analysis of battery sizing to match bus-driving requirements. The charging and vehicle-to-building dispatch of the electric school buses were optimized to evaluate the potential to reduce the impact of the bus charging on the school's electric utility bill. Distributed energy resources and flexible building loads were also considered with the school bus electrification to evaluate the further reductions in energy costs with enhanced systems integration and optimized dispatch. The effect of degradation on the school bus batteries was analyzed to determine if the smart-charging and vehicle-to-building battery operation decreases the life of the battery. The results show that there is an opportunity to mitigate the increase in electric utility bill with improved charging controls and bi-directionally operating the school bus batteries. The battery degradation analysis using dispatch with optimized charging and discharging shows that acceptable battery life remains.