Reducing bearing wear in induction generators for wave and tidal current energy devices

Marine energy devices such as wave energy converters and tidal current turbines are set to play a significant role in contributing to electricity generating by renewable means. The offshore location where these devices operate demands high reliability and robust fault tolerance. Bearing failure is a key issue for renewable energy devices and is a cause of significant downtime in wind turbines. Bearing wear is accelerated due to unbalanced magnetic pull in the rotor of an electrical generator. This paper presents a review and assessment of methods to reduce bearing wear through both machine design and active control through power electronics.