any given operating point, this Danish
turbine basically has to operate at constant
speed.
The construction and performance of
fixed-speed wind turbines very much depends
on the characteristics of mechanical
subcircuits, e.g., pitch control time
constants, main breaker maximum
switching rate, etc. The response time of
some of these mechanical circuits may be
in the range of tens of milliseconds. As a
result, each time a gust of wind hits the
turbine, a fast and strong variation of
electrical output power can be observed.
These load variations not only require a
stiff power grid to enable stable operation,
but also require a sturdy mechanical
design to absorb high mechanical
stresses. This strategy leads to expensive
mechanical construction, especially at
high-rated power.