Increase of Load Frequency Using Mechanically Synchronized Generators in Rotating Opposition

This paper discusses the possibility of a compact mechanical synchronization for electric generators driven by wind turbines or water flux aiming to increase the electrical frequency of the load voltage. This technique can reduce the rates of mechanical gearboxes or switching rates of electronic power converters. This new alternative besides reducing the ratio of the gear multipliers can even totally eliminate them in distributed generation. To prove this principle, it is proposed the use of two electric machines connected in opposition on a single shaft to add their frequencies in order to approach a resulting frequency compatible with the public network or as close as possible to it. Simulations of the proposed circuits were performed in PSIM software and verified in laboratory tests.