Control Structure Related Admittance-Shaping Effects in VSM Controlled Converters

This paper contributes to understand the admittance-shaping effects of the underlying control loops related to a converter controlled as a virtual synchronous machine. Here, two different voltage controller implementations are investigated with respect to their passivity and damping properties. This involves how the inertia model shapes the admittance of a virtual synchronous machine. Moreover, the sensitivity of inertia model design regarding the considered voltage controller implementations is identified. In addition to controller implementation sensitivities, it is elaborated how passivity properties may be improved by means of adequate filtering methods as well as an adaption in control structure, namely the voltage drop via the virtual stator model.