An energy sharing scheme based on distributed average value estimations for islanded AC microgrids

Abstract

Autonomous, self-governing micro energy networks are a smart energy solution that satisfy the energy needs of isolated communities. Such smart micro networks usually comprise of several distributed semi-controllable power resources, storages and loads. Usually, the power generation sources draw their energy from renewable energy resources. Power electronics converters suitably condition the power to be transmitted and utilized. A sensory, control and communication layer ensures the integration of several network components to achieve stable network operation. Distributed power-sharing methods function at local processing and decision-making nodes across the energy network. The complete control scheme is a hierarchical structure divided into four control levels. Faults and latencies experienced at the communication network layer adversely affect the performance of the control scheme. This paper proposes a new and improved hierarchical, multi-agents-based control strategy for efficient power-sharing, voltage and frequency regulation between nodes during communication link latencies. A novel distributed averaging estimator is proposed to estimate power injected in the system at various nodes and thereby mitigate the effect of relayed information delays. The effectiveness of the proposed strategy is established comprehensively through mathematical modeling, analytical proofs, discrete-time small signal stability analysis, and MATLAB case study simulations.