Virtual Inertia Control and Multi-time Scale Control Parameter Design of CHB-BESS

As the penetration rate of renewable energy continues to increase, the inertia of the power grid has significantly weakened. Battery energy storage based on cascaded H-bridges (CHB-BESS) has significant technical advantages in large-capacity energy storage systems and is more suitable for improving the inertia level of power systems. In order to solve the problem of insufficient system inertia, this paper proposes a virtual inertia control method based on CHB-BESS. Then, the control parameters of the proposed strategy are optimized and designed based on the multi-time scale characteristics of power electronics to ensure the dynamic and stable characteristics of the system. This method can effectively increase inertia and reduce frequency drop depth through damping and inertia links. Finally, based on the CHB-BESS simulation model, the effectiveness of the proposed control strategy was verified.