DMPC-based load frequency control of multi-area power systems with heterogeneous energy storage system considering SoC consensus

The energy storage system (ESS) has been widely used for the load frequency control (LFC) of power systems. The heterogeneous ESS (HESS) consisting of various types of energy storage units (ESUs) with different regulation characteristics creates many difficulties in designing a high-performance LFC strategy for a multi -area power system. To obtain the satisfied dynamic response of the LFC scheme against load disturbances and keep the state of charge (SoC) balance of the HESS, this paper proposes a distributed model predictive control (DMPC) method to design the LFC strategy. Firstly, the dynamic model of the power system with HESS is established. Then, the distributed predictive model for LFC design is formulated by considering the LFC objective, the SoC balance requirement, and the operational constraints of the generators and the HESS. Subsequently, the optimal LFC strategy is obtained by solving the distributed predictive model based on the linear quadratic programming (LQP) method. Finally, we make case studies to validate the effectiveness of the proposed method. Compared with the PI-based LFC, the proposed DMPC-based LFC performs better in stabilizing the system frequency, narrowing the area control error (ACE), and keeping the SoC of all the ESUs consistent.