Permanent Magnet Generators (PMG)
It is used in those cases in which it
What is a PMG?
does not matter if the
A permanent
voltage drops a certain
magnet generator is a
degree or when electronics
s y n c h r o n o u s
are applied to the output of
generator in which the
the generator.
excitation coil,
normally in the rotor,
has been replaced by a
system made up of
The electronics can convert
permanent magnets
a voltage range into
which provide a
continuous voltage of a
constant excitation
constant value.
field.
What applications does it have?
How does it work?
The PMGs manufactured by
The operation of the PMG differs
Obeki are used, for example, to feed
greatly from a normal synchronous
the regulators which act in the
generator. In a normal generator, voltage
excitation of large synchronous
is controlled by means of excitation. In a
generators. The main benefit in these
PMG, excitation is constant
cases is that when there is a
which is why, when the
short-circuit in the large
generator is charged, voltage
synchronous generator, they
drops without the option to
are capable of supplying the
regulate.
energy necessary to the
regulator so that it can
What is it used for?
overexcite the generator and
Permanent Magnet Generators, OBEKI S.A .Page 1 of 5
maintain the voltage sufficient time so
that the protections can start.
Another important use for our
generators is wind power generation. By
means of Obeki wind turbines, brushes
and differential systems are eliminated,
saving on maintenance, space and price.
Permanent Magnet Generators, OBEKI S.A .Page 2 of 5
What advantages does it have?
type, are capable of working at up to
140ºC, 80ºC magnets being the
The main advantage is its
standard.
simplicity. The manufacturing and
Obeki uses Neodym Cobalt
assembly of the rotor is cheaper if
magnets since they have the best
magnets are used. They do not need
properties.
maintenance because they do not have
In the case of wind turbines,
brushes. The mechanical consistency of a
the magnets can be a problem since
PMG is superior, in addition to not needing
they generate reluctant pairs which
systems for its excitation. By eliminating
do not allow for the start-up of the
the excitation, energy savings of 20% can
generator at low wind speeds. Obeki
be had by simply using magnets. By being
c o n f i g u re s t h e g e n e r a t o r s t o
an energy source which is independent
eliminate this effect.
from the generator, it can serve to supply
energy to auxiliary systems of the main
What is the voltage supplied by the
generator.
PMG like?
What are the magnets like?
The wave shape generated by
t h e P M G ca n a l m o st b e s i n e
The magnets used by Obeki are
depending on the intended use. The
cutting edge to
construction shape of
ensure their
the rotor where the
o p t i m u m
magnets are placed
operation. Normal
are
magnets, when the
influence. Obeki
magnetic circuit
manufactures PMGs
t h a t s u r ro u n d s
with low harmonic
them, lose their
levels, a single
of
great
magnetization, while those used by Obeki
magnet per pole, inclining the slots of
maintain them, which is why the rotor can
the stator, etc.., or of a greater
be separated from the stator without the
harmonic level, simple construction,
fear of losing magnetic properties. The
lesser cost. The selection of one or
magnets used by Obeki, depending on the
Permanent Magnet Generators, OBEKI S.A .Page 3 of 5
a n o t h e r d e p e n d s o n t h e c l i e n t ’s
specifications.
Permanent Magnet Generators, OBEKI S.A .Page 4 of 5
What voltages does it provide?
How so I adapt it to my machine?
The voltage supplied
To ease its clients’ work, Obeki
depends on the magnets, the coil and the
adapts them to their needs. Obeki
revolutions. Obeki precisely calculates the
manufactures the PMGs so that they
output and adapts it to the client’s needs,
can be connected to the attachment
capable of supplying different PMGs at the
the client needs.
same voltage for different speeds. Obeki
manufactures PMGs from 200 rpm to 3600
rpm.
Obeki configures its PMG to assure their optimum operation, simplicity
in assembly and construction to provide a simple, robust, reliable, stable,
adaptable and profitable product to its clients.
Permanent Magnet Generators, OBEKI S.A .Page 5 of 5