Secure Voltage-Modulated Vector Current Control of Distributed Energy Resources Using Delayed DSOGI Under Distorted and Unbalanced Grid Conditions

This article presents a vector current control (VCC) method for distributed energy resources (DERs) to achieve secure control and enhanced power quality under distorted and unbalanced grid conditions. We consider the impact of voltage distortion and unbalance on DER control and the role of phase-locked loop (PLL) when employing the dual second-order generalized integrator (DSOGI) approach to achieve high quality positive sequence voltage extraction under distorted and unbalanced conditions. Revealing the vulnerability of DSOGI PLL to adversarial parameter manipulation attack, we propose a delayed DSOGI voltage-modulated VCC (VM-VCC) scheme for DERs to mitigate the effect of distorted and unbalanced voltage on current injection by the DER. We further analyze the vulnerability of the delayed DSOGI and employ the concept of digital twin to achieve secure DER contol. Additionally, we present the implementation of the proposed delayed DSOGI-based VM-VCC for achieving balanced DER current injection during voltage unbalance. Comparative performance analysis conducted between the proposed approach and its DSOGI PLL counterpart demonstrates that, in addition to providing enhanced estimation, the proposed approach ensures robust and secure DER control performances.