Analysis and control of Distributed Energy Resources

Recent technology developments, including fuel cells, microturbines and efficient storage devices, have increased the possibility of employing Distributed Energy Resources (DERs) dispersed throughout the system. DERs are potentially valuable providers of ancillary services such as load following and contingency reserve in distribution systems. In this paper, slow dynamic models for microturbines and fuel cells are presented to explore the feasibility and benefits of providing energy and ancillary services from DERs at the distribution level. An adaptive power flow algorithm, derived from a compensation-based method, appropriate for the simulation of slow dynamics in the distribution system is also presented. An optimal distribution power flow strategy is presented for the coordinated dispatch and operation of DERs. The algorithm decomposes the overall system problem into two components: economic dispatch for energy and ancillary services based on market prices at the system level; and loss minimization at the distribution level. For real time operation of DERs at distribution level, an AGC type control strategy is also presented.