Research on ILADRC Multiple Parallel PV Energy Storage GFM VSG System Control Strategy

Grid forimg (GFM) converters have been gradually promoted and applied in engineering practice owing to their ability to provide effective voltage and inertial support. With a high proportion of renewable energy sources being connected to the power grid, the grid-source interaction between the distributed power sources and power grid is further enhanced. To ensure the stable operation of the distributed power sources and suppress the instability of grid-source interaction in GFM inverters under a strong power grid, an improved line active disturbance rejection control (ILADRC) multiple parallel photovoltaic (PV) storage GFM virtual synchronous generator (VSG) system control strategy is proposed. First, impedance modelling of single and multiple parallel PV energy storage VSG systems is established for stability analysis using Gale circle stability criterion. Second, ILADRC method is designed, and impedance modelling of ILADRC multiple parallel PV energy storage GFM VSG system is established for stability analysis. Finally, an ILADRC multiple parallel photovoltaic energy storage GFM VSG simulation model and hardware-in-the-loop experimental platform are established for tests. Test results show that ILADRC multiple parallel photovoltaic energy storage GFM VSG system has better grid-source interaction stability under a strong power grid and grid harmonic background than parallel virtual impedance/unimproved method.