Implementation of Discretization Methods for Second-Order Generalized Integrator in Grid Voltage Estimation Systems

Abstract

The second-order generalized integrator (SOGI) has been receiving a great deal of attention recently for the grid voltage estimation owing to its excellent harmonic rejection capability. In practice, such an algorithm is usually implemented by digital devices, thus the accurate discretization of the SOGI is essential to achieve the desired system performance. A comprehensive study about the discretization of the SOGI for grid voltage estimation is presented in this paper, in which the performance comparisons of SOGI discretized by various methods, i.e., backward Euler method, Tustin method, ZOH method, impulse invariant method, are conducted. Through the thorough analysis and simulation results, the proper discretization method for the SOGI for grid voltage estimation has been recommended.