A real-time distributed storage system for multi-resolution virtual synchrophasor

Abstract

With the continuing large-scale deployment of Phasor Measurement Units (PMU), the Wide-Area Measurement System (WAMS) technology is envisioned to evolve towards a distributed architecture where multiple sets of distributed Phasor Data Concentrators (PDCs) collectively process PMU data to achieve real-time distributed intelligence. Emerging applications developed under this vision will pose stringent but heterogeneous real-time requirements on throughput, delay, and reliability performance of the underlying communication and computing infrastructure. To address this problem, we present a novel virtual PMU (vPMU) architecture that decomposes phasor samples into multiple resolution layers. For a particular receiver with a certain resolution requirement, a complete set of PMU data can be composed by combining samples from the lower layers, without the need for samples from higher layers. We design and implement a real-time distributed storage system to support the virtual PMU data communication. We extend the Chord algorithm so that the response time of data communication can be bounded by our storage system. In addition, we use queuing theory to analyze the response time of requests with our stochastic model.