Analysis of Active Phase Jump Power Dynamics and Their Mapping to Grid-Forming Capability of VSCs

Active phase jump power is introduced to assess the slow internal voltage source (IVS) behavior of grid-forming voltage-source converters (GFM-VSCs), which is an essential GFM capability requirement. However, the high-order dynamics of GFM-VSCs hinder a clear theoretical understanding of how the IVS behavior shapes the power response trajectory. To tackle this issue, this article develops an analytically tractable time-domain model for the active phase jump power, which leads to a rather unexpected finding: the commonly adopted 10 ms rise-time metric of the active phase jump power is inadequate for identifying the slow IVS behavior, risking incorrect judgments in practical compliance testing. Therefore, a novel duration-based metric, underpinned by two evaluation criteria, is proposed. The theoretical findings and the effectiveness of the proposed method are validated through simulations and experimental tests.