Multimode Controller Design for DSTATCOM integrated  with Battery Energy Storage for Smart Grid Applications

A Distribution Static Compensator (DSTATCOM) can provide reactive power support, power factor correction and voltage regulation to a distribution system feeder. In this paper, a multimode multifunctional control algorithm is proposed for the controller of the Voltage Source Converter (VSC) to provide DSTATCOM and load leveling functionalities for smart grid applications through a Battery Energy Storage System (BESS) connected to the grid through the VSC. The designed controller enables the VSC to function in both grid-connected and standalone modes of operation. In grid-connected mode, the VSC provides load leveling, dynamic reactive power exchange and unity power factor functionalities based on consumer's choice. When a fault occurs on the grid, the controller opens the circuit breaker and isolates the load from the grid and then switches to the voltage controller for the standalone mode of operation. The novelty of the proposed controller is, the inverter structure which provides load leveling and DSTATCOM functionalities during grid-connected mode will also serve the load during a grid failure, thereby providing uninterrupted power supply to the load. The simulation results show the ability of the proposed multimode controller to successfully operate the multifunctional DSTATCOM-BESS system in various modes.