A Reverse Droop Control for More Adjustable Grid-following Inverters Under Weak Grid

Grid-forming (GFM) control has been considered as the solution of the inertia problem for traditional power grid caused by high proportion of new energy. Due to the limitation of capacity ratio, when the capacity of GFM inverters cannot guarantee the stable operation of the power grid, letting grid-following (GFL) inverters participate in the active support of the power grid is also a potential method. In this article, a reverse droop control method is introduced to GFL inverters, and a detailed state-space model is established. By comparing with the traditional GFL inverters, the proposed reverse droop GFL inverters is proved to have a better performance in maximum power output capability, weak power grid adaptability and a more robust parameter settings boundary with tolerance deviations. Simulation results are used to illustrate the accuracy of the established model and the correctness of the conclusions obtained.