Compact power converter with high waveform quality for direct-drive renewable energy generators

Offshore wind turbines are being deployed with increasing power ratings to take advantage of the reduced cost of electricity achievable with larger machine sizes. The power conditioning system and transformer that interface the wind generator to the grid are a critical part and there is an industry need to make them more compact, reliable, easier to install and service, and capable of cleaner waveforms. The objective of the proposed work is to develop a compact power conditioner using wide-band gap semiconductors and high frequency transformers for interfacing offshore wind machines such newly developing superconducting generators with high voltage (69 kV) collection grids. A multi-level scalable power conditioner topology with novel high frequency and high voltage isolation will be developed. An advanced power conditioning system approach will be developed including topology, power components selection, and controls to address challenges of advanced very high-power wind turbines and marine hydrokinetic (MHK) turbines. The work to be done includes computer modeling and simulation of the topology and controls. Preliminary design and prototype testing of the insulation approach to handle a 69 kV grid connection will be carried out. Interactions between the power conditioner and a superconducting generator will be studied using computer models developed by Fastwatt and GE. Benefits of the new power conditioning system include reduced size and weight which will make it easier to install and service in offshore turbines. The technology can also be used for other applications such as solar farm integration, locomotives, and offshore oil and gas installations.