Discrete-time implementation of second order generalized integrators for grid converters

Second order generalized integrators (SOGI) have been proposed to obtain zero steady-state error using stationary frames in grid-converters applied to active rectifiers, active filters, uninterruptible power supplies and distributed generation. These integrators have been also included in algorithms of grid synchronization, detection of sequences, harmonic compensation, etc. Due to all these algorithms are implemented over digital processors, it is very important to make a correct discretization to optimize their behaviour. This work is focused in this topic. An exhaustive study about different methods to implement the SOGIs in the discrete-time is achieved, proposing a common structure for the different SOGI applications, including proposals of C program and presenting a comparative analysis about the execution time using different digital structures.