摘要
With photovoltaic(PV)sources becoming more prevalent in the energy generation mix,transitioning grid-connected PV systems from grid-following(GFL)mode to gridforming(GFM)mode becomes essential for offering self-synchronization and active support services.Although numerous GFM methods have been proposed,the potential of DC voltage control malfunction during the provision of the primary and inertia support in a GFM PV system remains insufficiently researched.To fill the gap,some main GFM methods have been integrated into PV systems featuring detailed DC source dynamics.We conduct a comparative analysis of their performance in active support and DC voltage regulation.AC GFM methods such as virtual synchronous machine(VSM)face a significant risk of DC voltage failure in situations like alterations in solar radiation,leading to PV system tripping and jeopardizing local system operation.In the case of DC GFM methods such as matching control(MC),the active support falls short due to the absence of an accurate and dispatchable droop response.To address the issue,a matching synchronous machine(MSM)control method is developed to provide dispatchable active support and enhance the DC voltage dynamics by integrating the MC and VSM control loops.The active support capability of the PV systems with the proposed method is quantified analytically and verified by numerical simulations and field tests.
基金
supported in part by the National Key R&D Program of China(No.2022YFB2402900)
the National Natural Science Foundation of China(No.U2066601)。
