Decentralized multivariable vector current control of grid-connected voltage source inverters

Increasing the number of grid-connected inverters in power systems imposes several challenges. One of the main challenges is the complexity and uncertainty of the dynamical model of the inverters due to the large numbers of grid-connected inverters and disconnection of inverters. To address this challenge, we present a scalable direct-quadrature current control strategy for parallel voltage source inverters in a rotating reference frame. The control structure is based on a decentralized multivariable proportional integral (PI) current control mechanism and provides stability and zero steady-state errors. The proposed control approach has the main advantages of flexibility, allowing disconnection/connection of inverters on the basis of the required power level. The effectiveness of the proposed vector current control strategy is evaluated through simulation case studies in MATLAB/Simscape Electrical.