Deliverables Power electronics technology for variable-speed generation The main result is the capability of using an asynchronous machine in variable rotational speed generation (between the synchronous speed and about twice its value). In a wave energy plant, this enables the air turbine to respond efficiently to a wide range of sea states, and (by flywheel effect) produces a short-term smoothing effect on the electrical power delivered to the grid. The asynchronous machine with slip energy recovery requires that, for given maximum power, the rated power of the machine and that of the converter are both half the total power. The generator is based on a simple, reliable and inexpensive machine, whose technology is well established. The power converter is a Current Source Inverter (CSI) using IGTBs in PWM operation, which generates a very low harmonic content current into the grid. The use of a variable speed electrical generator is one of the most important and innovative features of the Pico plant. Using a modified version of the asynchronous machine, whose technology is well established, is the simplest way of achieving that goal. The machine will perform as a generator at speeds above the synchronous speed and as a motor below that speed. As the system is able to control the converted power over a wide operating speed range, the know-how acquired can be used in other applications requiring variable speed generators (e.g. wind energy converters). Wave power plant design. Performance and cost analysis The main result of the project is the design and construction of a full-sized OWC prototype (400 kW) that produces electrical energy from the ocean waves. This is the first fully-automated, industrial-sized wave energy plant, permanently connected to a small electrical grid, and presents several important innovations, namely variable speed generation, Wells turbine with guide vanes, controlled relief valve, plant control. The analysis of the plant's performance provides important information to validate design criteria, control procedures and reliability of the plant's equipment. This, together with cost analysis, are important contributions to enhance the competitiveness of wave energy. The pilot plant can be used as a platform for testing power equipment and control software. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
