A 4 MW variable speed drive for a research and development aerodynamic wind tunnel

The range of performance analyses and the technical challenges to be overcome when engineering a large drive system are described. To illustrate these points the design of a 4 MW wind tunnel impeller drive is used as a basis for discussion. This drive powers a 9 metre diameter aerodynamic wind tunnel fan at the Honda research and development centre in Tochigi, Japan and it is believed to be one of the largest drives used in this type of application. The use of an inverter fed synchronous motor in a wind tunnel is a rarity, DC drives having dominated this market for many years. However, the inverter fed AC drive offers distinct advantages over its DC counterpart, as is highlighted by the authors