Algorithm and realization of threephase gridconnected inverter synchronous control based on DSP

YU Ning, HE Tongneng, WANG Zekai

(College of Information Engineering, Zhejiang University of Technology, Hangzhou 310023, China)

Abstract: Aiming at the inverter and power gridconnected security, need to be in parallel before phase synchronizing control, to ensure that big circulation won′t be produced during the grid process. The TI company DSP F28335 was used as an example, and the continuous increase or decrease counting mode was used to produce symmetrical PWM wave to reducing harmonic. SVPWM was adopted to control threephase output by threephase inverter. Through the zerocrossing detection circuit, the grid inverter zero phase was detected, and it was used for the calculation of the inverter power supply phase comparison, according to the phase difference that carries on the corresponding algorithm adjustment, the phase synchronization was realized. To improve the precision of adjustment, the phase was divided into phase lead and lag phase. According to the difference phase, the corresponding adjustment was undertaken. The results of the study show that, the phase synchronization control realized by this method in the simulation model and the practical effect is very good, inverter and grid can realize safe grid.

Key words: threephase inverter; grid; synchronizing control; DSP; phase