Compared with the traditional generator, the permanent magnet synchronous generator of the rare earth permanent magnet motor does not need the collector ring and the brush device, so the structure is simple and the failure rate is reduced. Rare earth permanent magnet can also increase the air gap flux density, and the motor speed to the best value, improve the power quality ratio. Modern aviation, aerospace generators with almost all rare earth permanent magnet generators. The typical product of the United States General Electric Company made 150kVA14 pole 12000r / min ~ 21000r / min and 100kVA60000r / min rare earth cobalt permanent magnet synchronous generator. The first rare earth permanent magnet motor developed in China is 3kW20000r / min permanent magnet generator.
Permanent magnet generator is also used as a large-scale turbo generator deputy exciter, the successful development of our country in the 80's at that time the world's largest capacity of 40kVA ~ 160kVA rare earth permanent magnet secondary exciter, with 200MW ~ 600MW turbine generator greatly enhance the operation The reliability.
At present, small-sized internal combustion engines driven by independent power generators, permanent magnet generators for automobiles, and small permanent-magnet wind power generators directly driven by wind turbines are gradually being popularized.
Compared with induction motor, permanent magnet synchronous motor with high efficiency can reduce power factor (up to 1 or even capacitive), reduce stator current and stator resistance loss, No rotor copper loss, which can reduce the fan (small capacity motor can even remove the fan) and the corresponding wind friction loss, efficiency than the same size induction motor can be increased by 2 to 8 percentage points. Moreover, permanent magnet synchronous motors maintain high efficiency and power factor within 25% to 120% of the rated load range, resulting in more significant energy savings in light-load operation. Such motors are generally set in the rotor starting winding, with a frequency and voltage at the direct start of the ability. Currently mainly used in oil fields, textile and chemical fiber industry, ceramic glass industry and the long run fan pumps and other fields.
Article from NdFeB Industry Network