How Many Grid-Forming Converters Do We Need? A Perspective From Small Signal Stability and Power Grid Strength
Grid-forming (GFM) control has been considered a promising solution for accommodating large-scale power electronics converters into modern power grids thanks to its grid-friendly dynamics, in particular, voltage source behavior on the AC side. The voltage source behavior of GFM converters can provide voltage support for the power grid, and therefore enhance the power grid (voltage) strength. However, grid-following (GFL) converters can also perform constant AC voltage magnitude control by properly regulating their reactive current, which may also behave like a voltage source. Currently, it still remains unclear what are the essential differences between the voltage source behaviors of GFL and GFM converters, and which type of voltage source behavior can enhance the power grid strength. In this paper, we will demonstrate that only GFM converters can provide effective voltage source behavior and enhance the power grid strength in terms of small signal dynamics. Based on our analysis, we further study the problem of how to configure GFM converters in the grid and how many GFM converters we will need. We investigate how the capacity ratio between GFM and GFL converters affects the equivalent power grid strength and thus the small signal stability of the system. We give guidelines on how to choose this ratio to achieve a desired stability margin. We validate our analysis using high-fidelity simulations.
Code (0)
등록된 구현이 없습니다.
Similar Papers 제목 키워드 기반
New perspectives on transient stability between grid-following and grid-forming VSCs
The grid-following and grid-forming controls in voltage-source converters are considered as different operation modes and the synchronization mechanism of them are studied separately. In this article, the intrinsic relat…
On Power Control of Grid-Forming Converters: Modeling, Controllability, and Full-State Feedback Design
The popular single-input single-output control structures and classic design methods (e.g., root locus analysis) for the power control of grid-forming converters have limitations in applying to different line characteris…
Placing Grid-Forming Converters to Enhance Small Signal Stability of PLL-Integrated Power Systems
The modern power grid features the high penetration of power converters, which widely employ a phase-locked loop (PLL) for grid synchronization. However, it has been pointed out that PLL can give rise to small-signal ins…
Control of Grid-Forming VSCs: A Perspective of Adaptive Fast/Slow Internal Voltage Source
Grid-forming (GFM) capability requirements are increasingly imposed on grid-connected voltage-source converters (VSCs). Under large grid disturbances, GFM-VSCs need to remain stable while providing GFM services. Yet, suc…
Quantifying Grid-Forming Behavior: Bridging Device-level Dynamics and System-Level Stability
Grid-Forming (GFM) technology is considered a promising solution to build power electronics-dominated power systems. However, the impact of GFM converters on the system stability is still unquantified, creating a gap bet…