Stability Analysis of a Hybrid Wave-Energy Conversion System with Linear Permanent-magnet Generator Driven by Archimedes Wave Swing and Induction Generator Driven by Wells Turbine

Abstract

This paper presents the stability simulation results of a hybrid wave-energy conversion system (WECS) consisting of two equivalent aggregated linear permanent-magnet generators (LPMGs) driven by two Archimedes wave swings (AWSs) and an equivalent aggregated grid-connected squirrel-cage rotor induction generator (SCIG) driven by a Wells turbine. The two equivalent aggregated AWS-LPMG sets are fed to the same power grid through two voltage-source converters (VSCs) and a voltage-source inverter (VSI). The q-d axis equivalent mathematical models of each subsystem of the studied hybrid WECS are derived under three-phase balanced loading conditions. The steady-state results and the root-loci plots of the studied WECS under different operating conditions are performed. Transient and dynamic simulations of the studied WECS system subject to a three-phase fault and different wave-force conditions of the two equivalent aggregated AWS- LPMG sets are also carried out, respectively. The simulation results shows that the studied hybrid wave-energy conversion system can be maintained stable operation under various disturbance conditions.