Direct - drive permanent magnet synchronous generator design for hydrokinetic energy extraction

Hydrokinetic turbines deliver lower shaft speeds when compared to both steam and wind turbines. Hence, a water wheel generator must operate at speeds as low as 150 - 600 rpm. This thesis describes a permanent magnet synchronous generator (PMSG) that was designed, built, and tested to serve a low speed hydrokinetic turbine. The design methodology was emphasized since designing an application specific generator poses various design and hardware construction issues. These are torque, speed, power and start-up requirements. This generator was built to operate without a speed increaser, implying very low speeds. FEA and performance results from the simulation done in ANSYS - RMXprt® and Maxwell® 2D respectively are presented. The hardware test results demonstrate that the generator performs satisfactorily while reducing the cogging torque to the greatest possible extent --Abstract, page iii