This series of motors operate at synchronous electrical speed, with no slip between the stator and rotor. During stable operation, there is no copper loss or iron loss in the rotor, which can reduce the fan and accordingly decrease the wind friction loss. Since rare earth permanent magnet motors do not require reactive excitation current, the power factor can be significantly improved to the limit value (1.0). It can adapt to various load conditions, has obvious energy-saving effects, operates reliably and safely, has low substitution costs, and a short payback period. It has been recommended by the national "Motor System Energy Conservation Project".