Blade Dynamics specialises in building and designing blades for high-power wind turbines of 5MW and over.
AMSC said the trend for greater capacity turbines was a major factor in the decision to invest in the company.
The deal will allow AMSC to offer Blade Dynamics products to its licensees, which include Hyundai, and for its own upcoming 10MW SeaTitan wind turbine.
Dow Chemical Company has also made a "minor equity investment".
Additionally, Blade Dynamics will set up a new facility in New Orleans, Louisiana.
AMSC acquires 25% of Blade Dynamics
US - Wind component manufacturer American Superconductor Corporation (AMSC) has acquired a 25% stake in UK blade manufacturer Blade Dynamics.