Development of a Droop Control Strategy for Flexible Operation of Distributed Generators

Abstract

Droop control is one of the control strategies utilized to establish a simple, effective, and a communication-less power sharing between several distributed generators (DGs) in power systems and microgrid networks. In this paper, the control of an inverter-based system operating with the proposed droop control is developed and analyzed. The proposed droop control with its adjustable nonlinearity level aims to flexibly control the DGs in order to fulfill multiple objectives that aim to stabilize the operation of the sources and optimize the power sharing. These objectives can be achieved, simultaneously, as the droop characteristics generated under the proposed control cover all the possible operating points in the frequency-active power (f-P) and voltage- reactive power (V-Q) planes. The capability of the proposed control strategy to construct highly non-linear characteristics enables the DG to effectively meet different complex technical and economic constraints. The work carried out in this paper focuses on the f-P droop relation, and investigates the system performance under different physical and control parameters. The obtained results show that the proposed droop control is able to perform well under different operating conditions, shape the power sharing of the running DGs and stabilize the system performance.