Four new applications of Second-Order Generalized Integrator Quadrature Signal Generator

The Second-Order Generalized Integrator (SOGI) was used as a building block for the SOGI-Quadrature-Signal Generator (SOGI-QSG) which has been widely used for grid synchronization, frequency estimation, and harmonic extraction over the past decade. This paper further investigates its integration and differentiation characteristics, with four new integrators and differentiators proposed. Theoretical analysis shows that the proposed SOGI-QSG based integration and differentiation methods can effectively overcome the drawbacks of the pure integrator and differentiator. The proposed four new methods are the frequency-adaptive integrator, the frequency-adaptive differentiator, the frequency-fixed integrator and the frequency-fixed differentiator respectively. The effectiveness of the proposed methods and the correctness of the theoretical analysis are finally evaluated by experimental results.