Synchronization Technique for PV-Wind-Battery Based Grid Forming Converter with DFIG

Abstract

This paper presents an islanded operation of wind turbine driven doubly fed induction generator (DFIG), photovoltaic (PV) array and battery based microgrid. Here local grid (LG) is formed by a PV-battery-based grid forming converter. Depending upon the wind availability the doubly fed wind turbine driven induction generator (DFIG) is synchronized with LG. The maximum PV power is extracted through the incremental conductance (INC) algorithm. The battery is connected across the DC-link of the grid forming converter. The LG terminal voltage is maintained by grid forming converter. The field-oriented control (FOC) is used to control the rotor side converter (RSC). Moreover, it is used to extract the maximum wind power and provides reactive power to the DFIG. A Discrete Fourth-Order Generalized Integrator-Frequency Locked (DFOGI-FLL) control is used to maintain the DC-link of the grid side converter (GSC). Moreover, it mitigates the reactive power to the LG and calculates the stator angle (Ɵstator), After matching the vstator, fstator and Ɵstator of the DFIG, it synchronizes to LG. Simulated results show performance of the PV-wind-battery based grid forming converter with DFIG synchronization in different conditions.