Experimental evaluation of a doubly-fed linear generator for ocean wave energy applications

A versatile doubly-fed linear generator was recently presented for application in the point absorber ocean wave energy converter (WEC). While this machine may be operated as a singly- or doubly-fed induction machine or via a self-synchronous approach, operation as a synchronous machine is found to be an attractive method for experimental testing. Using this mode of operation, the generator may be run with a DC field in either the translator or stator, thus producing power from the stator or translator respectively. Given the unique hybrid-flux architecture of this linear generator, synchronous testing in this manner provides a way to quantify the difference in electrical and reactive force production between the translator and stator topologies under WEC operating conditions, i.e. low speed with high force. This paper presents the testing procedure and setup along with detailed prototype results.