The study of phase-locked and grid connection control strategy for commutatorless motor

In order to solve the engineering difficulty of electrical-grid-connection technology for commutatorless motor without impact, some analysis and researches have been done in depth in this paper. It gives digital Phase-Locked-Loop to adjust motor frequency and phase, and closed-loop excitation plot to regulate Back-EMF. Software PLL algorithm applies the zero-crossing-point phase-detector to compute the phase difference of grid and motor. It coordinates with speed-loop and electricity-loop, and coordinates with the excitation control. It verifies the feasibility of the theory through the MATLAB simulation, and realize the grid connection without impact in the hardware platform experiment.