A cascaded converter-based StatCom with energy storage

Due to their advantages in high power applications, multi-level converters have been introduced to flexible AC transmission systems (FACTS) to enhance power transmission system operation. Although several multi-level StatCom topologies have been proposed to verify the high performance of multi-level converters used in reactive power compensation, they are not capable of controlling active power flow. To make multi-level converters more flexible and effective for active power flow control, energy storage systems, such as flywheels and batteries are incorporated into StatComs. In this paper, battery energy storage systems (BESS) are incorporated into a cascaded converter-based StatCom to implement both active and reactive power flow control using a PQ-decoupled PI control strategy. Furthermore, the dynamics of the integrated system in damping power oscillations are studied using an electromagnetic transient program PSCAD/EMTDC. Simulation results are provided to verify the feasibility and practicality of these ideas.