FPGA implementation of harmonic detector based on Second Order Generalized Integrators

A system-on-chip harmonic detector, based on FPGA technology, is proposed in this paper by using second order generalized integrators (SOGI). Two structures denominated DSOGI-QSG (dual SOGI- quadrature signal generation) tuned to a specific frequency allow detecting the positive and negative sequences of the specified harmonic. A bank of DSOGI-QSGs is presented as a multiple harmonic detector by adding multiple feedbacks between the DSOGIQSGs. This scheme is called MSOGI-QSG. This paper proposes a discrete fixed-point FPGA-based design of a MSOGI-QSG which is focused on the algorithm refinement and modularity. The approach is implemented and tested with a Spartan 3 (XC3S200) FPGA (field-programmable gate array).