40kw 250rpm Hydro Turbine Permanent Magnet Electric Generator
Manufacturer
Product Drawing
Technical Parameter
Detailed Pictures
The structure
The design of a PMG is relatively simple. It consists of a rotor,
stator, and permanent magnets. The rotor is a rotating shaft that
contains permanent magnets. The stator is a stationary component
that surrounds the rotor and contains the coils of wire. When the
rotor spins, the magnetic field created by the permanent magnets
cuts across the coils of wire in the stator, inducing a voltage.
Working Principle
The permanent magnet generator uses the principle of
electromagnetic induction in that the wire cuts the magnetic field
line to induce an electric potential and converts the mechanical
energy of the prime mover into electrical energy output. It
consists of two parts, the stator, and the rotor. The stator is the
armature that generates the electricity and the rotor is the
magnetic pole. The stator is composed of an armature iron core,
uniformly discharged three-phase winding, machine base, and end
cover.
The rotor is usually a hidden pole type, which is composed of
excitation winding, iron core and shaft, guard ring, center ring,
and so on.
The excitation winding of the rotor is fed with DC current to
generate a magnetic field close to the sinusoidal distribution
(called the rotor magnetic field), and its effective excitation
flux intersects with the stationary armature winding. When the
rotor rotates, the rotor's magnetic field rotates together with it.
Every time a revolution is made, the magnetic lines of force cut
each phase winding of the stator in sequence, and a three-phase AC
potential is induced in the three-phase stator winding.
When the pm generator is running with a symmetrical load, the
three-phase armature current synthesizes to generate a rotating
magnetic field with synchronous speed. The stator and rotor fields
interact to generate braking torque. The mechanical torque input
from the turbine overcomes the braking torque and works.
Features
●Low speed permanent magnet direct-drive generator. Do not need the
gearbox. The turbine connects with the PMG directly, simplifying
the structure and improving the system performance. The PMG can
output 50Hz directly at the rated speed.
●The gearbox reliability is not high. The system reliability can be
improved if there is no gearbox. That means less maintenance,
better utilization, longer lifespan for the system.
●The efficiency is high. The system efficiency can be improved
around 20% when you use PM generator without gearbox.
●The PMG can work efficiently throughout the whole speed range.
Less heat when working. The PMG can use natural air cooling.
●Low start up torque, the system can output power at low speed.
●The PMG works at low speed, low noise, more safe and reliable, the
lifespan of the bearings can be longer.
●The voltage, speed ,power of the generator can be customized. The
shape can also be changed, using spine shaft, dual shaft, front
edge or other output ways.
Application
PMGs are used in a variety of applications, including wind
turbines, hydroelectric dams, and wave energy converters. They are
particularly useful in situations where it is difficult or
impossible to connect to a power grid, such as remote locations or
offshore installations.
The classification of permanent magnet generator:
Permanent magnet generators (PMGs) can be classified based on
various factors, such as the type of magnet, the application, the
number of phases, and the power rating. Here are some common
classifications of permanent magnet generators:
Based on magnet type: a. Ferrite Magnet PMG: These generators use
ferrite magnets, which are less expensive and have a lower magnetic
strength than rare-earth magnets. b. Rare-Earth Magnet PMG: These
generators use neodymium or samarium-cobalt magnets, which are more
expensive but have a higher magnetic strength than ferrite magnets.
Based on application: a. Wind Turbine PMG: These generators are
designed for use in wind turbines and are typically used in
small-scale or off-grid applications. b. Hydroelectric PMG: These
generators are designed for use in hydroelectric power plants and
are typically used in large-scale applications.
Based on the number of phases: a. Single-phase PMG: These
generators have a single output phase and are used in low-power
applications. b. Three-phase PMG: These generators have three
output phases and are used in high-power applications.
Based on power rating: a. Low-power PMG: These generators have a
power rating of up to a few kilowatts and are used in small-scale
applications. b. High-power PMG: These generators have a power
rating of several megawatts and are used in large-scale
applications, such as wind turbines and hydroelectric power plants.
Future of Permanent Magnet Generator:
Based on current trends and advancements in technology, the future
of permanent magnet generators looks promising. These generators
are becoming increasingly popular in various industries, including
wind and hydropower generation, due to their high efficiency, low
maintenance, and reliability.
One of the significant advantages of permanent magnet generators is
their ability to generate power at low speeds, making them ideal
for use in low-wind areas and small-scale applications. They also
have a more compact design, which reduces the overall weight and
size of the generator, making it easier to install and transport.
With the growing demand for renewable energy sources, permanent
magnet generators are likely to play a significant role in the
future of energy production. As technology advances, these
generators are expected to become more efficient, cost-effective,
and versatile, making them suitable for a broader range of
applications.
Overall, the future of permanent magnet generators looks bright,
and they are likely to continue to be a popular choice for
renewable energy production.
