Transient Stability Analysis and Virtual Power Compensation of a Virtual Synchronous Generator Under Low-Voltage Fault
Bo Long, Chengkun Hu, Zhihao Chen, Jiefeng Hu, José Rodríguez
Abstract
Virtual synchronous generators (VSGs) demonstrate similar damping and inertia characteristics to traditional synchronous generators, thereby enhancing their ability to support grid voltage and frequency. However, VSGs face challenges related to overcurrent and power angle instability during low-voltage fault conditions. To enhance the low-voltage fault ride-through capability of VSGs, this article introduces a virtual power compensation (VPC) strategy combined with an enhanced current limiting method. First, the transient stability of VSGs with current limiting is analyzed to reveal its instability mechanism. Second, the operational mechanism of the proposed VPC strategy in enhancing transient stability is examined. By means of phase portraits, the effect of transient stability improvement by the VPC is described. Additionally, to facilitate the selection of control parameters, a detailed quantitative analysis has been conducted. Finally, hardware-in-the-loop experiments validate the effectiveness of the proposed control scheme.