PMSG based grid integrated wind energy conversion system with controlled power injection

This paper deals with a PMSG (Permanent Magnet Synchronous Generator) based WECS (Wind Energy Conversion System) integrated with the grid for controlled active power injection. Two back-back connected VSC´s (Voltage Source Converters) are used with a common DC bus supported by a BESS (Battery Energy Storage System) to facilitate power generation at variable speeds of a PMSG to achieve MPPT (Maximum Power Point Tracking) and controlled injection of active power to the grid. The MPPT is achieved using an OTC (Optimal Torque Control) technique for the generator side VSC. The grid side VSC is controlled using VOC (Voltage Oriented Control) technique. The objective of controlling the grid side VSC are to smoothen the output power under wind intermittency and dispatching constant power to the grid based on SOC (State of Charge) of battery. To inject controlled active power to the grid, an active control scheme is designed for the grid side VSC. The performance of the developed control algorithm is demonstrated under changes in wind speeds and SOC of the battery.