Abstract
<title>Abstract</title> <p>Low-speed wind turbines frequently operate under highly variable wind conditions, where efficient electrical energy conversion depends on the interaction between turbine characteristics and generator behaviour. Although extensive research has focused on improving Savonius turbine aerodynamics, comparatively little attention has been devoted to passive electrical matching between the turbine and the generator. This study investigates whether the inherent winding inductance of a stepper motor generator can be intentionally exploited together with an external compensation capacitor to establish passive electrical resonance within the operating-speed range of a Savonius wind turbine. Electrical resonance is experimentally investigated using two permanent-magnet stepper motors operated as generators. The experimentally identified resonance region is compared with the measured operating characteristics of a Savonius wind turbine and subsequently interpreted using a simplified mathematical model. The proposed approach introduces passive resonance-based electrical matching as a simple design concept for improving electrical energy conversion in low-speed wind-energy systems without actively controlled power-electronic converters. The simulations identified an optimum resonance compensation interval between 40 and 50 µF, where the electrical resonance is best aligned with the aerodynamic operating region of the turbine. The configuration with tuneable capacitance proposes the highest overall integrated performance.</p>