Pinning-based distributed droop control of power converters in isolated AC microgrids

Accurate active power and reactive power sharing is one of the key control objectives for autonomous operations of isolated micro-grids (MGs). Traditionally, this task is achieved by decentralized droop control. Since such class of decentralized droop control may lead to inaccurate power sharing under the system with non-uniform transmission lines, various methods have been proposed to overcome this difficulty. Due to the rapid developments of information and communication technologies in recent years, multi-agent systems (MAS) have had a tremendous breakthrough. This MAS technology has also been applied into MG control. In this paper, one special MAS control, called pinning control, is proposed to improve the performance of the power sharing. Since only a small fraction of agents in the networks have access to critical information, the required communication bandwidth can be significantly reduced in comparison with the recent consensus-based droop control. Theoretical studies of this pinning-based distributed droop control will be presented in details. Software developments and extensive simulations are conducted by the Java Agent Development Framework (JADE) and Matlab/Simulink. Performance evaluations are conducted by extensive simulations of a test-bed MG in Taiwan. Simulation results confirm the feasibility and the accuracy of the proposed pinning-based distributed droop control.