Estimation of Damping Effects in a Salient Pole Synchronous Machine without a Damper Using SSFR Testing with a VSI

Abstract

Accurate estimation of damping effects in salient pole synchronous machines is essential for improved modeling and stability analysis. Although the application of the Standstill Frequency Response (SSFR) method to machines without damper windings has been discussed in previous studies, this work focuses on demonstrating its practical applicability using a Voltage Source Inverter (VSI) with a sine filter to ensure highquality excitation signals. The objective is to evaluate whether SSFR can effectively capture damping phenomena arising from eddy currents and magnetic saturation in the pole structure, even in the absence of explicit damper bars. Experimental tests are carried out under controlled standstill conditions, and the resulting frequency responses are analyzed to identify dampingrelated characteristics. The results confirm that, with proper excitation and measurement setup, the SSFR method remains valid for such machines. This study contributes by validating a practical, inverter-based approach for SSFR testing, offering enhanced precision and applicability in modern synchronous machine analysis.