With the rapid develop of new energy units, the power system is increasingly exhibiting characteristics of low inertia, weak support capability, and poor disturbance rejection. The capability to provide dynamic reactive and active support is inadequate, exacerbating voltage and frequency stability challenges. To address these issues, this paper proposes the design of an 11.1 MVA AC excitation synchronous condenser (AC SynCon). First, the working principles and modes of the AC SynCon are elaborated. Subsequently, the design methods and constraints of the AC SynCon are presented. Finally, a two-dimensional finite element method (FEM) simulation model is established to analyze its electromagnetic performance under both steady-state and transient conditions. The results indicate that the AC SynCon possesses both reactive power support capability and short-term high-overload active power output capability, which can overcome the limitations of conventional DC excitation synchronous condensers.

AC Excitation Synchronous Condenser; Electromagnetic Design; Performance Analysis; Finite Element Simulation