Abstract: Based on the magneticfieldoriented vector control principle, a microstep drive control strategy for the permanentmagnet synchronous motor (PMSM) is proposed in this paper. By maintaining a constant statorcurrent vector and evenly varying vector position, the amplitude of the stator MMF is unchanged while its position moves smoothly, so as to orient the solar array toward the sun. The results show that the proposed microstep drive control method achieves the drive performance when the solar array drive mechanism drives the simulated solar array load. The given torque current is suggested to be selected according to the power efficiency and solar array driving speed stability in the design and implementation process. The effectiveness of the control method is further confirmed. The control method can be used in engineering practice.

Key words: solar array drive mechanism, PMSM, microstep drive, space vector pulse width modulation, stability