POWER COORDINATION CONTROL STRATEGY FOR DISTRIBUTED HYBRID ENERGY STORAGE SYSTEM BASED ON CCS-MPC

Aiming at addressing the problem of coordinated operation in distributed Hybrid Energy Storage Systems (HESS) for DC microgrid systems, a power coordinated control strategy based on Continuous Control Set Model Predictive Control (CCS-MPC) is proposed. The strategy comprises upper and lower layers. The former implements power distribution, using wavelet packet transform to decompose the power demand to the supercapacitors and batteries. Moreover, the adaptive factor is utilized to distribute battery power demand based on the State of Charge (SOC) of the battery to achieve SOC consistency. The lower layer, namely CCS-MPC, uses distributed control, where each DC/DC converter is associated with a model predictive controller. In order to verify the effectiveness of the proposed method, an island DC microgrid model containing distributed HESS was built and compared with the multi-agent consistency control algorithm using a distributed PI controller. The results confirmed that the proposed strategy can effectively reduce DC bus fluctuations and achieve consistent battery SOC faster. In addition, this strategy improves the stability of power grid operation and extends the service life of batteries.