Novel Multi-Station Integrated System and Coordinated Control Strategy

Current large-scale access to distributed power and rapid growth of electric vehicles are seriously affecting power quality and reliability of distribution networks. The above issues can be resolved by using a multi-station integrated system (MSIS) composed of an energy storage system, distributed generation (DG) system and transformer substation. This paper proposes a new topology and coordinated control strategy for MSIS. The top control layer receives dispatching commands from the power grid superior to realize top layer control. The soft normally open point (SNOP) receives instructions from the top control layer to realize high-degree-of-integration mode of generation-network-load-storage. Remaining converters and energy storage devices receive instructions to realize access and integration of distributed power stations, such as energy storage systems, electric-vehicle charging systems, and photovoltaic (PV) power systems. Eight working schemes of the autonomous operation of the system are analyzed. The small-signal model of the MSIS is derived. Feasibility of the proposed topological structure and control strategy for achieving a hierarchical power supply of MSIS can be verified by real-time digital simulation results.