The task in this project is to design a generator for a vertical axis wind turbine with power rated to 20kW at a wind speed of 10m/s. The design has just a few moving parts, which decreases maintenance costs and increases its toughness. The turbine absorbs wind from every direction but its rotation speed ratio is lower than horizontal axis wind turbines.
It means that the generator must be bigger and therefore more expensive. Price is an important criterion for the generator. Neodymium magnets are expensive so the amount of this material must be limited. Several designs have been simulated but one final design has proven the most promising. It fulfills all specifications such as efficiency above 95%, 20kW output power and it also has a relatively low amount of hard magnetic material.A design with a single row of cables per slot was decided upon to eliminate heat pockets between cable rows, which can occur in designs with two cable rows per slot. It would be interesting to study designs with two or more cable rows per slot, as it could lead to a smaller and more efficient machine.
Source: Uppsala University
Author: Rynkiewicz, Mateusz