It depends on the efficiency of the motor. The efficiency and power factor of permanent magnet synchronous motor are mutually restricted. Motors with the same power and rated current have high efficiency and low power factor; On the contrary, if the efficiency is low, the power factor is high. The dynamic mathematical model of permanent magnet synchronous motor is nonlinear and multivariable, including the product term of ω and id or iq. Therefore, in order to obtain accurate dynamic control performance, ω must be decoupled from id and iq.