An electric generator includes multiple coil sections and switches connected to the multiple coil sections for selectively interconnecting the coil sections in series, or in parallel, or in a series-parallel configuration across first and second power terminals for producing a controlled AC voltage across these power terminals. The electric generator, with its multiple coils and interconnecting switches permitting reconfiguration of the coils, enables systems subjected to widely varying conditions and forces, such as a wave energy converter (WEC), to be operated with increased efficiency. The generator may also include multiple windings which can be selectively interconnected into a wye or a delta configuration to also control the output voltage produced by the generator and increase the efficiency of the power conversion system, particularly at low values of voltage.