Active Power Nodes for Increased Energy Resources Availability in Distribution Networks

This paper explores the effects of modular, multiple-input multiple-output (MIMO) power electronic interfaces with embedded energy storage on the availability of distributed energy resources, i.e. photovoltaics and energy storage, within a DC-based distribution network. These effects are evaluated both quantitatively and experimentally with Monte Carlo simulations. The chosen MIMO converter interface, referred to as an active power distribution node (APDN), utilizes bi-directional ports and embedded energy storage to achieve both power-routing and power-buffering functionality as well as selectively promote the utilization of connected sources and loads. The detailed approach to evaluating availability uses Markov chain models to characterize a system’s operation and minimal cut sets (MCS) to determine the availability of the system’s power supplies. The main contribution of this work is derived from exploring the benefits of availability analysis incorporating simultaneous MCS – a phenomenon that is generally ignored for systems without modularity and embedded energy storage due to the high probability of an individual MCS over a simultaneous pair of MCS. It is important to evaluate the impact of such features on a distribution system both in terms of its electrical performance and availability benefits.