SPLL design to flux oriented of a VSC interface for wind power applications

Accurate phase information is crucial for most of modern power electronic systems such as VSC connected to the grid. In this paper, it is proposed an algorithm software phase-locked loop (SPLL) to obtain phase and frequency information of the grid voltage. This is based in an algorithm of on-line separation of the grid voltage sequences (DSC), and a discrete traditional PLL. A criterion to tune the SPLL constants from a PLL discrete linearized model is discussed. The SPLL response is evaluated for different grid disturbances and different SPLL parameters. Besides, a VSC connected to the grid through and L filter with the SPLL obtained in this paper has been tested for different configurations of SPLL and different grid perturbations. Conclusions about where to apply the SPLL different configurations are obtained from these last tests.