Development of the C-GEN generator technology for vertical axis wind turbines

Abstract

In this thesis, 5 MW, 7.5MWand 10MWat 6 rpm C-GEN generator models were designed and optimized respectively for a vertical axis wind turbine. Although VAWTs have lower rotational speed than HAWTs, the offered C-GEN VAWT generators have significant higher power density compared to conventional PM and superconducting HAWT generators of equivalent power. The inner radius of the 5 MW C-GEN generator is 5.35 m and mass is 41.2 tonnes. The inner radius of the 7.5 MW C-GEN generator is 5.35 m and active mass is 44.1 tonnes. The inner radius of the 10 MW C-GEN generator is 7.50 m and active mass is 41.6 tonnes. Annual generation results show that offshore VAWT can generate as much energy as HAWT of the same power. In addition, by the end of 2022, the most powerful single offshore HAWT is 14 MW and due to the tower head mass of HAWTs, it is limited to increase the power further. Multi-power platform VAWTs can take the power of a single turbine further.

The C-GEN model with wavy and comb steel structure has higher power density than the C-GEN model with straight steel structure. In addition, in the multi-stage C-GEN models, the comb steel structure will allow the passage of air between the stages, and since the wavy steel structure has more surface area than straight steel, it can help to increase the thermal performance of the machine. Since machine mass is an important factor in aviation, automotive propulsion systems and renewable energy converters, these structures can provide advantage. The machines are analysed and optimised electromagnetically using 2-D FEA simulations.

A software algorithm has been developed for the simulations. This algorithm allows any electrical machine to be modelled and optimized easily and quickly. In addition, this algorithm can be applied to 3-D models and other branches of engineering such as mechanical, civil, naval, aircraft and etc. for use CAD and FEA models.