permanent-magnet synchronous motor is mainly composed of rotor, end cover and stator. permanent magnet means that the motor rotor carries high-quality permanent magnet, and synchronization means that the rotation speed of the rotor is equal to the rotation "magnet" generated by the stator.
the biggest difference from other motors lies in the unique structure of the permanent magnet installed on the rotor. the location of the permanent magnet also produces different types, which are mainly divided into surface-mounted, plug-in and embedded.
because the alternating current and the distribution structure of the winding will produce a rotating magnetic field, we can obtain ac power to the special winding in the stator through the familiar uvw three-phase line. according to the principle that the magnetic polarity repels the opposite attraction, the rotating magnetic field will drag the rotor with the permanent magnet in the middle, until the rotating speed of the rotor reaches the speed of the rotating magnetic field, the motor will enter a stable working state.
according to its unique structure, permanent magnet synchronous motor has the following advantages:
good cooling system:
the heating of permanent magnet synchronous motor is small, so the motor cooling system has simple structure, small size and low noise.
the system adopts a fully closed structure, without transmission gear wear, transmission gear noise, lubricating oil and maintenance.
permanent-magnet synchronous motor allows large overload current and significantly improves reliability; the whole transmission system is light in weight, the spring weight is lighter than the traditional shaft transmission, and the unit weight power is large; because the permanent magnet synchronous motor has no gearbox, the vehicle power performance is greatly improved; the rotor is free of copper and iron damage, collector ring and brush friction loss, and has high operation efficiency.
the rotor of permanent magnet synchronous motor adopts permanent magnetic material poles, especially rare earth metal permanent magnets (such as neodymium iron boron, etc.). its magnetic energy product is high, and high gap magnetic flux density can be obtained. therefore, when the capacity is the same, the motor is small in size and light in weight.
small rotating inertia, large allowable pulse torque, high acceleration, good dynamic performance, compact structure and reliable operation.
can be used as generator:
because the characteristics of permanent magnet synchronous motor can be used as an efficient generator, it can also meet the energy recovery function of new energy vehicles.