Time Domain Aggregation of Generating Units for Shipboard Power Systems

An improved time-domain online dynamic equivalent method is presented, which is suitable to shipboard power systems (SPS) and based on the coherency technique. It preserves the structure of the generator, excitation system and governor system, and the time-domain non-iterative algebraic operations process is used to calculate equivalent parameters. Sixth-order generator equation is used to reduce the grid considering the subtransient. Formulas and the aggregation steps are come out. The method is applied to reduce an eight generators and fourteen buses SPS in PSCAD/EMTDC environment, equivalent parameters and dynamic response curves are presented. Simulation curves show that the equivalent system retains the dynamic performance of the original system with good accuracy.