With recent revision of the IEEE 1547 standard that now for the first time allows distributed generation to regulate voltage at the point of common coupling, numerous research groups have started exploring unconventional ways to control grid-interface converters. Such change incontrovertibly requires new concepts for advanced control of all energy flows in order to improve system stability, energy availability, and efficiency. Consequently, high dispersion of renewable energy sources will highly depend on engineers' capability to understand, model, and dynamically control power sharing and subsystem interactions. This paper presents, with deep insight, how to control power converters as synchronous machines of any type in d-q coordinate system; more precisely, by formally establishing electromechanical-electrical duality, understand which parameters of power converters relate to which parameters of isotropic or anisotropic synchronous machines.