Electromagnetic Interference from Wind Turbines - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 543

9
Electromagnetic Interference
from Wind Turbines
Dipak L. Sengupta, Ph.D.
Professor of Electrical Engineering
University of Detroit Mercy
Detroit, Michigan
and
Thomas B. A. Senior, Ph.D.
Professor of Electrical Engineering
The University of Michigan
Ann Arbor, Michigan
Introduction
It is well known that any large structure, whether stationary or moving, in the vicinity
of a receiver or transmitter of electromagnetic signals may interfere with those signals and
degrade the performance of the transmitter/receiver system. Under certain conditions, the
rotor blades of an operating wind turbine may passively reflect a transmitted signal, so that
both the transmitted signal and a delayed interference signal (varying periodically at the
blade passage frequency) may exist simultaneously in a zone near the turbine. The nature
and amount of electromagnetic interference (EMI) in this zone depend on a number of
parameters, including location of the wind turbine relative to the transmitter and receiver,
type of wind turbine, physical and electrical characteristics of the rotor blades, signal
frequency and modulation scheme, receiver antenna characteristics, and the radio wave