BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI - Universitatea ...

178 Mihai Florin Mănescu and Valeriu Panaitescu
emphasized the efficiency of plants used as feedstock in electricity generation,
renewable sources. Unlike other renewable energy sources, wind energy is
limited because of its technological maturity, good infrastructure and relative
price competitiveness. To have an effective higher cost-benefit, wind generators
groups have become increasingly high.
Some of the problems arising from the operation of wind turbines are listed
below:
a) the areas where wind farms are developed wind regions and which are
usually difficult to reach, such as high mountain areas or areas of Dobrogea, due
to existing infrastructure;
b) the height of pillars (about 100 m), which makes revisions and access
for repairs difficult;
c) there have been accidents that led to the collapse of the entire wind
structure and consequently to enormous losses;
d) the tendency to have a high cost-benefit led to large structures;
e) in Romania there isn’t a mature experience in the production of
electricity using wind power, the first wind turbine was put into service in 2005,
with a pillar height of 54 m. The wind farms that are now developed are usually
100 m high and, in case of damage, this fact can lead to serious accidents, since
action plans may not be effective.
Given the above, it becomes necessary to monitor the whole resistance
structure of wind turbines using a network of sensors.
The monitoring systems are safe and low-cost, and their implementation can
prevent energy losses during revisions or damage. These systems can efficiently
diagnose which parts of the wind turbine must be replaced and they can also
work to reduce duration of a scheduled review. Furthermore, these systems can
predict the life cycle of the plant whose working time averages10-30 years.
According to F a r r a r and S o h n [1] a monitoring system is defined as a
process that detects faults which occur in high buildings. A fault is defined here
as a alteration of the materials and / or of the geometric properties of these
systems, including alterations in bordering conditions and system connectivity,
which adversely affect system performance. There can be many causes of
structural damage such as moisture absorption, fatigue, wind gusts [2], thermal
stress, corrosion, fire and even lightning [3].
In general, the successful development of methods of MSR depends on two
key factors: the technology employed for detection and signal analysis and the
algorithm for interpretation [4]. MSR components consist of a data acquisition
system, data filtering, pattern recognition and decision making. Each of these
components is equally important in determining the safety status of a structure
[5].
The monitoring process involves well-timed observation, using data from a
series of sensors and statistical analysis in determining the status of the
structure. In the case of long-term process MSR, the sensors provide regularly