Power quality enhancement through ancillary services provided by power electronic converters

Modern electrical power grids are susceptible to several problems in terms of power quality due to the integration of renewable energy sources, the connection of nonlinear loads, and power electronics-based devices. In this sense, this work proposes a novel nonlinear control scheme that allows, through the use of a power electronic converter, to provide ancillary services to the electrical power grid, intending to achieve three different control objectives: voltage regulation, harmonic distortion compensation, and the power factor correction at a power system node, depending on the end-user requirements, and by doing so enhance the power quality. The proposed control scheme uses nested control loops based on super-twisting sliding modes, nonlinear optimal tracking control, and a fast-convergent harmonic estimator with a decentralized structure. Simulation results validate the effectiveness of our proposed scheme.