Analysis on the direct-driven high power permanent magnet generator for wind turbine

Rotor demagnetization effects on permanent magnet synchronous machines

“…7b presents the analysis of the failure for branch a1 current, for the same load conditions. The indicator of fault is given by the magnitude of the components at 1 2 f s and 3 2 f s , which increase as demagnetization increases. The difference between phase and branch currents is due to a circulating current through the two branches.…”

“…In both cases, faults are responsible for high costs due to maintenance and downtime. Recently, fault detection in PMSM has become more noticeable due to the impulse given to the development of renewable energy sources and the increasing tendency to use these machines as generators directly coupled to wind turbines [1,2]. There exist several proposals for monitoring wind turbines, as for instance fault detection in electric generators [3], which mainly aims to reduce maintenance costs.…”

Design of a wind turbine generator for rural applications

“…Outer rotor topology was adopted due to the advantages it offers in the construction and assembly of the generator [6]. Regarding the stator windings, double-layer fractional pitch windings are used in order to reduce cogging torque and copper losses.…”

“…These gear boxes increase the system costs, producing in addition a decrease in its overall performance. They also require more maintenance due to they are the major cause of failure in wind turbines, producing also unwanted noise [6,7].…”

“…Most PMSMs use surface-mounted magnets in an inner rotor [6]. Chen et al, on the other hand, proposes the use of axial-flow geometries of permanent magnet (PM) assembly, which are appropriate for high number of poles [10].…”