A Novel Dynamic Rotor Interturn Short Circuit Model on Rotor Electromagnetic Vibration Investigation for Synchronous Generators

In the early stages of a Rotor Interturn Short Circuit (RISC) for synchronous generators, the short circuit is often unstable and intermittent, leading to what is known as a Dynamic Rotor Interturn Short Circuit (DRISC). However, most existing research primarily addresses the stable form of the short circuit, termed Static Rotor Interturn Short Circuit (SRISC). In this article, a novel DRISC model is proposed to assess the generator condition quickly and accurately. The model considers key parameters such as the number of shorted turns, the position of the short circuit, the contact resistance, and the load power. The model successfully explains the electromagnetic vibration behavior of the rotor, which is influenced by the DRISC. To validate the DRISC model, finite element calculations and experiments are conducted on a 5 kW prototype generator. The rotor mechanical response is obtained due to the unbalanced magnetic pull (UMP), which aligns with the DRISC model prediction. This article provides essential theoretical support and a computational process paradigm for condition assessment under the DRISC fault in synchronous generators, augmenting existing research systems on RISC.