In this paper, a stationary-frame, single-loop controller for three-phase standalone inverter supplying nonlinear loads has been derived from synchronous reference frame proportional-integral multiloop controller. In this method, load voltage harmonics are eliminated by a single loop and only one control variable. The proposed method has several advantages such as lack of Park transformation and requires tuning only one control parameter. It can also be implemented with less computational burden, less complexity, and easier tuning, compared to conventional proportional-integral multiloop controller. Experimental results with laboratory prototype under linear and nonlinear load conditions validate the proposed method.

A category structure for Bratteli diagrams is proposed and a functor from the category of AF algebras to the category of Bratteli diagrams is constructed. Since isomorphism of Bratteli diagrams in this category coincides with Bratteli’s notion of equivalence, we obtain in particular a functorial formulation of Bratteli’s classification of AF algebras (and at the same time, of Glimm’s classification of UHF algebras). It is shown that the three approaches to classification of AF algebras, namely, through Bratteli diagrams, K-theory, and a certain natural abstract classifying category, are essentially the same from a categorical point of view.