A Reduced-Order Matrix-Based Approach for Short-Circuit Simulation of Single-Phase Transformers

Transformers are critical components in power systems, and their short-circuit faults pose significant risks to the safe and stable operation of the grid. In engineering practice, the transient characteristics of fault conditions can be analyzed using either finite element models (FEM) or equivalent circuit models. FEM can accurately simulate the transient characteristics under multiple physical fields. However, such simulations are computationally intensive and time-consuming. In contrast, equivalent circuit models enable fast simulation of short-circuit faults, but fully coupled representations often result in complex model structures that are difficult to handle. To address this challenge, this paper proposes a model order reduction method for high-order self and mutual inductance matrices. An equivalent simplified model of a single-phase transformer is constructed based on the reduced-order inductance representation. Simulation studies are conducted using a singlephase testing transformer, validating the accuracy and equivalence of the reduced-order model. The proposed approach provides a theoretical and practical foundation for rapid simulation of transformer short-circuit faults.