Dead-time compensation method of single-phase AC excitation for three-stage brushless synchronous machines

A method was proposed to acquire the distorted one-phase excitation alternating current directions of the exciter in the starting mode of three-stage brushless synchronous starter/generator system for the dead-time compensation of the single-phase H bridge inverter. A three-parameter sine wave curve-fit algorithm which can fit sin waves in real time using the present sample current was adopted. Thus, the present sample current could be modified and current directions could be determined. Meanwhile, the sliding-window iterative algorithm was used to reduce the calculation amount of three-parameter sine wave curve-fit method. The results show that the three-parameter sine wave curve-fit algorithm optimized by sliding-window iterative method can estimate current directions well when the excitation current of the exciter is distorted seriously. Thus, the dead-time compensation of the single-phase H bridge inverter can be realized in the starting mode of three-stage brushless synchronous starter/generator system with the exciter excited by one-phase AC.