Consensus-Based Hybrid Multiagent Cooperative Control Strategy of Microgrids Considering Load Uncertainty

Abstract

The energy management systems used in microgrid systems are either centralized or decentralized. The centralized method is easy to implement, but has low reliability and it is computationally intensive due to its reliance on a single control unit. The decentralized control is a more reliable strategy as multiple units are coordinated to manage the microgrid system, however, its algorithm and implementation are complicated for long-term operation. This paper proposes a consensus-based hybrid multi-agent management system including both centralized and decentralized agents taking advantages of both methods into account. The hierarchical cooperative optimization system is adapted for the distributed economic dispatch. The primary control layer is responsible for the voltage and frequency regulations whereas the secondary control layer is implemented in a consensus-based distributed multi-agent control scheme for optimal microgrid management. The centralized agent is used to optimally schedule the energy storage system. The proposed hybrid control strategy consistently maintains the economic operation and demand load balance of the microgrid system under load uncertainty. A comparison study with the centralized control strategy is presented to demonstrate the effectiveness of the proposed control strategy. The feasibility of the proposed controller is validated by the control-hardware-in-the-loop simulation using OPAL-RT Technologies. Real-time simulation results show that the proposed hybrid strategy has a better optimization performance compared to the centralized strategy under load uncertainty conditions.

Keywords

• Economic dispatch
• hybrid multi-agent cooperative system
• load uncertainty
• microgrid