A DC Power-Based Scheme to Detect Loss of Field in Synchronous Generators

This paper proposes a new scheme to detect loss of field (LOF) phenomenon in synchronous generators. The presented scheme employs the exciter output voltage and current signals to calculate the DC power injected into the generator field circuit. It is shown that any LOF failure in the field circuit, interrupt the DC power delivery to the rotor winding so that by selecting simple settings for the scheme, such interruptions are easily detected. To evaluate the proposed scheme performance, simulation studies are carried out by employing the phase domain (PD) model of the synchronous generator available in the real-time-digital-simulator, while the PD model allows simulating different realistic LOF failures. Obtained results show that the proposed scheme can easily detect different LOF failures.