Shipboard electrical power quality of service

Although the U.S. Navy has decreed that the primary aim of the electric power system design is for survivability and continuity of the electrical power supply, metrics have never been developed for continuity of service. This paper examines design issues associated with providing continuity of service under other than combat damage conditions and proposes a quality of service (QOS) metric to aid shipboard power systems design. This QOS metric is based on the probability that the power system provides the degree of continuity of power that each load needs to support the ship´s missions. The major factors impacting QOS are the ratings, reliability and failure modes of the prime movers, power conversion equipment, and load equipment as well as system configuration. Additionally, while design features for QOS often improve system survivability, different failure modes require the designer to consider both survivability and QOS.