Abstract

The frequent penetration of distributed energy resources in microgrid environment often faces operational challenges like stability and reliability issues. In order to overcome these challenges, the concept of the virtual power plant is suggested. Practically, the chance of voltage and frequency fluctuation increases in virtual power plant scenarios under critical power system contingencies like faults and sensitive load switching. Therefore, implementation of efficient controllers is required to address this issue. Further, the fixed gain droop control topology reported in literature is insufficient to accomplish seamless voltage and frequency regulation of the virtual power plants. Therefore, this paper proposes an adaptive droop control scheme to regulate system’s frequency and voltage (as per IEEE 1547) in presence of critical power system contingencies under virtual power plant scenarios. Further, a small signal stability analysis is carried out considering the system Eigenvalues to investigate the effectiveness of the proposed adaptive droop controller. Additionally, a comparative analysis between traditional and proposed droop controller is performed considering critical power system contingencies under MATLAB / Simulink environment. The dynamic responses establish the improved performance of the proposed controller over the traditional control scheme in terms of transient and steady-state stability.

Key words: adaptive droop control scheme, distributed energy resource, frequency regulation, small signal stability, virtual power plant, voltage regulation