Frequency estimation with antiwindup to improve SOGI filter transient response to voltage sags

Abstract

The SOGI filter is a simple structure that allows to accurately obtain the parameters of the grid voltage with a small computational burden. There are different structures proposed and some allow to obtain the parameters under adverse faulty conditions. However, this filter shows to be especially sensitive to voltage sags and phase jumps. Then, this paper proposes a simple antiwindup technique for the frequency estimation that limits to a great extent the transient response of the filter to these perturbations. The proposal is simple and improves the response of the system. Simulations are provided to validate the proposal.