System Identification Based Grid Agnostic Adaptive Droop Control Strategy

This paper investigates the implementation possibilities of the recently proposed system identification-based adaptive droop control scheme under varying grid conditions. The paper also provides a detailed analysis of the impact of reactive droop parameter on the power decoupling. At the distribution level, the feeder impedance comprises of both, inductive and resistive components, leading to the problem of power coupling. To counter the problem of power coupling an adaptive droop control strategy was proposed that tunes the reactive droop coefficient while respecting the trade-off between reactive power sharing accuracy, small signal stability and the voltage drop. In this paper, two main contributions are presented. Firstly, a mathematical relationship is deduced that shows the impact of reactive droop coefficient on the coupling between active and reactive power. This relationship offers a comprehensive understanding for selecting suitable tuning parameters for adaptive droop control. Secondly, the performance of the proposed controller is evaluated over a wide range of grid impedance compositions through simulation. The results demonstrate that (i) increasing reactive power droop coefficient has a marginally diminishing effect on the power decoupling, which aligns with the mathematical deduction and (ii) the system-identification based droop controller can be implemented in any grid, irrespective of its impedance composition, making the controller grid-agnostic.