Rotor Side Control of Wells Turbine Driven Variable Speed Constant Frequency Induction Generator

Abstract

Wave energy can meet a sizeable portion of the world's energy needs. For countries having long coastlines, wave energy conversion is an attractive proposition. Wells turbine driven grid–connected systems with squirrel cage induction generators have been in existence; however, rotor–side control of grid–connected induction machine is an attractive option for variable speed constant frequency operation. The power rating of the converter can be considerably reduced when used in the rotor circuit over a limited slip range (approximately 50%). Since the stator is directly connected to the grid, the stator flux is constant over the entire operating region. Therefore, the torque can be maintained at its rated value even above synchronous speed. This article describes the simulation of a rotor side chopper controller for wave energy.