Control and synchronization of a marine substation

Sammanfattning: Wave energy is a renewable energy source with great potential. Series of different techniques have been developed to achieve a power plant that can convert the kinetic energy in the waves to electrical energy. One of these concepts has been developed at Uppsala University. The converter is a linear direct driven permanent magnet generator, placed on the seabed, driven by a buoy on the ocean surface. The output voltage from the linear generator varies both in amplitude and frequency. To be able to feed the output voltage to the grid, the voltage is converted to suitable properties and synchronized with the grid voltage. Different methods to achieve the synchronization have been investigated. Simulations in the software program Simulink and LabVIEW FPGA have been performed. The substation includes a tap-transformer with five different taps on the primary side. Different systems to achieve a safely on load tap change were investigated. The results from the investigations are based on simulations in Simulink, LabVIEW FPGA and calculations, and are well consistent with the theory.