Computationally Efficient Formulation of Flywheel Energy Storage System Components for Real-Time Power Systems Simulation

For real-time electrical power system simulation applications, computationally efficient, numerically stable and accurate models are sought. In this paper, two approaches to produce efficient and accurate models of a low-speed flywheel energy storage system (FESS) are assessed. First, an efficient and numerically stable custom induction machine model, to be used in a detailed power system FESS model, is built combining phase domain and dq quantities for the RSCAD-RTDS environment. Secondly, a reduced order model of the machine side subsystem is used to improve the model efficiency. The numerical stability and accuracy of both approaches is assessed by numerical simulations using an RTDS station. The results obtained show the advantages of the proposed formulations over conventional models.