The main objective of the IMAGINE project (“Innovative Method for Affordable Generation IN ocean Energy”) is to develop a new Electro-Mechanical Generator (EMG) for wave energy applications: a ground-breaking technology that can decrease by over 50% the CAPEX of current PTO technologies, while increasing average efficiency above 70% and lifetime to 20 years.
During the reporting period (up to month 18) it was expected to deliver results of Work Packages 2, 3, 4, and 5.
WP2 – EMG integrability analysis and specifications
K2M (previously CA) performed an estimation of the loading environment across relevant design load cases (DLCs) for combinations of target installation sites and WEC types. The combinations allowed the creation of a detailed PTO load envelope that in turn contributed to the design of the EMG (WP3), test bench (WP4) and control system (WP5). WP2 simulation models will provide the calculated PTO input‖ for the HWIL simulation of WP6.
WP3 – EMG prototype design and fabrication
The completion of WP2 provided a set of specifications for EMG prototype design and fabrication. Specifications mainly concern axial screw force, speed, stroke and required damping values for optimal power capture. Based on this the EMG design took place and the main prototype components have been designed to ensure they withstand the design loads and they can be manufactured/assembled with existing processes/tools. In addition, BV M&O performed a FMECA to obtain a preliminary assessment of EMG reliability.
WP4 – HWIL test bench design and fabrication
This WP is dedicated to the definition of the test plan for the EMG and HWIL test bench design and fabrication. WP4 start was triggered by WP2 outputs (EMG specifications) and by partial results of WP3 (EMG prototype). The HWIL testing scheme has been developed integrating on the test bench the control systems defined in WP5 and numerical models developed in WP2. The bench has been developed by VGA and will be operated by UMBRA. In parallel, BV M&O will review all the documents and procedures to help in aligning them to the requirements of a future certification process.
WP5 – Control systems design and implementation
WP5, led by NTNU, used the EMG prototype system design parameters (defined in WP2) and physical constraints such as maximum torque, speed and stroke (derived from WP2 and WP3) as input in order to identify PTO control strategies that can optimize EMG overall power performance. Some control alternatives have been evaluated taking into consideration EMG efficiency at partial load. A number of representative test cases have been analysed, representing both steady state and typical operational transients to identify the most promising control strategy. All the simulation models will be implemented to ease the subsequent implementation in HWIL testing platform in WP6.
