Three-phase to single-phase direct connection rural cogeneration systems

This paper proposes a solution for the direct connection of a three-phase induction generator to a single-phase feeder. This high quality power system is intended to be used in micro-hydro power plants, without control of the turbine. The generated power that is not consumed by the local load is driven to the single-phase feeder. The power flow control is provided by a three-phase PWM inverter, which guarantees the local power quality and controls the power flow through the single-phase feeder. This converter allows balancing the induction generator currents, voltages and frequency. The paper describes the inverter control strategy, presents design criteria of the controllers and shows experimental results.