Power take-off for a wave energy converter

A wave energy converter comprising:

• a floating body;
• a reaction body engaging the floating body, said reaction body static or oscillating out of phase relative to the floating body;
• a power take-off (PTO) having
• at least one direct drive linear generator comprising
• a plurality of stators linked in series having lateral edges flush with one-another creating a single electric machine;
• and
• a translator having a plurality of translator modules, a stack of alternating electrical steel laminations and permanent magnets forming the plurality of translator modules, said plurality of translator modules mechanically connected at lateral edges of the translator by supports and matching the length of the linked stators plus an excess length in a direction of oscillatory travel determined to meet a desired stroke length of the direct drive linear generator, said PTO interconnected to a rod engaging the floating body;
• a high level controller responsive to one or more sensors engaged to the direct drive linear generator and providing a PTO force change command (dDPTO);
• a low level controller receiving the PTO force change command and providing one or more control signals to one or more power electronics connected to the direct drive linear generator, said direct drive linear generator operable responsive to the one or more control signals to achieve optimal power extraction performance with high force at low speed with operation in two physical directions and operating as both a motor and a generator for a total of four quadrants of control.

A method for wave energy conversion comprising:

• buoyantly supporting a floating body on a water surface;
• engaging the floating body with a reaction body, said reaction body static or oscillating out of phase relative to the floating body;
• engaging the floating body with a rod interconnected to at least one linear generator in a power take off (PTO), each of the at least one linear generators comprising
• a plurality of stators linked in series having lateral edges flush with one-another creating a single electric machine;
• and,
• a translator having a plurality of translator modules, a stack of alternating electrical steel laminations and permanent magnets forming the plurality of translator modules, said plurality of translator modules mechanically connected at lateral edges by supports and matching the length of the linked stators plus an excess length in a direction of oscillatory travel determined to meet a desired stroke length of the direct drive linear generator said supports interconnected to the rod engaging the floating body;
• engaging the plurality of stators to the reaction body for translation of the translator within the stators;
• and
• extracting electrical power from the PTO.