In this paper, a novel approach for comprehensive state-space modelling of the grid Connected multi-level inverters is proposed. Details of the developed method is presented using cascaded H-bridge converters, however it can be applied to other topologies of the grid Connected inverters as well. In multi-level converters, due to their nonlinear characteristic, application of the nonlinear controllers is more beneficial to ensure stability of the system in a wide range of operation. Hence, the state-space model is required to design a nonlinear controller. To achieve converter model, it is divided into some sub-circuits considering different operational intervals in a switching cycle. To verify accuracy and effectiveness of the obtained state-space model, a laboratory setup of a multi-level. Converter with two H-bridges has been designed and implemented. Also, results of the developed state-space model has been compared with the simulation/experimental results of the grid-Connected converter. According to the simulation and experimental result, accuracy of the model is verified. It should be noted that all of the simulations have been performed by EMTDC/PSCAD toolbox.

Background and Objectives: In this paper, a novel approach for regulation of the output current in the grid-Connected three-level flying capacitor inverter is presented by using the sliding mode (SM) method. In the proposed method, it is possible to control the active and reactive components of the inverter output current independently, and therefore it can be employed for grid connection of the renewable energy resources or for harmonic and reactive power compensation of the local loads. The designed controller uses an external loop to control the voltage of the inverter DC link and has a constant switching frequency. The stability of the proposed method has also been proved by using the Lyapunov stability theory. The simulation results show that in different operating conditions, the proposed controller has a stable and robust response. Methods: Grid-Connected three-level flying capacitor inverter is modeled by using averaged state space technique. Considering nonlinearity of the obtained model, an equivalent SM controller is developed for output current control of the multilevel grid Connected inverter. To improve robustness and stability of the system against uncertainty of model parameters, a nonlinear component is added to the equivalent controller. Results: The proposed controller enjoys very fast dynamic response, so it can be employed in wide ranges of application e. g. reactive compensation and harmonic mitigation modes. In active power filtering operation, it is able to eliminate harmonic components of the grid from 20. 61% to 1. 34% which is compatible with IEEE and IEC standards. Conclusion: The stability of the proposed method has also been proved by using the Lyapunov stability theory. The simulation results show that in different operating conditions, the proposed controller has a stable and robust response.

In this paper, we use the left(right) stabilizers of a BCKalgebra (X, *, 0) and produce two basis for two different topologies. Then we show that the generated topological spaces by these basis are Bair, Connected, locally Connected and separable. Also we study the other properties of these topological spaces.

The zero forcing number Z(G) of a graph G is the minimum cardinality of a set S with colored (black) vertices which forces the set V (G) to be colored (black) after some times. \color change rule": a white vertex is changed to a black vertex when it is the only white neighbor of a black vertex. In this case, we say that the black vertex forces the white vertex. We investigate here the concept of Connected zero forcing set and Connected zero forcing number. We discusses this subject for special graphs and some products of graphs. Also we introduce the Connected propagation time. Graphs with extreme minimum Connected propagation times and maximum propagation times |G| -1 and |G| -2 are characterized.

. In this paper we continue with our study of uniformly LipschitzConnected metric spaces. We obtain further properties of uniformly LipschitzConnected metric spaces and then obtain a generalisation of a result due to Edelstein. In addition, we show that for a proper Lipschitz-Connected metric space, Ld = 1 precisely when X is convex, which leads us to conjecture that Ld is a kind of measure of convexity in a proper Lipschitz-Connected metric space. We provide some examples to corroborate our conjecture.

It is henceforth a commonplace; the science-fiction would be a refractory genre by nature against the definitive assimilation to the literary mainstream. We can say that the usual thematic of the genre, to which is added the irresistible propensity to prospect the future in all its forms, immunizes the SF against the “academic confinement” to the benefit of other forms of confinement. Indeed, the SF belongs to the great family of the paraliterature where the more or less listed subgenres are waiting to receive a likely definition. Popular genre which relies on a remarkable poetic, the SF is an open place to the imagination, to the verbal and the figurative creativity. It owns itself its subgenres, among other things, the space opera which was, in a way, the original matrix of the speculative fiction and of its contemporary imitators. The Sternberg’s work did not have a special vocation to feed the already rich world of the science-fiction. It constitutes however a new step liable to bring a touch of self-reflexivity, we will notice that, to the history of this genre. French: “Le Navigateur” de Jacques Sternberg ou la phylogenese parodiee du space opera C’est dorenavant un lieu commun, la science-fiction serait un genre par nature refractaire a l’assimilation definitive au mainstream litteraire. Nous dirons que les thematiques habituelles du genre, auxquelles viennent se meler l’irresistible propension a prospecter l’avenir sous toutes ses formes, immunisent la SF contre “l’enfermement academique” au profit d’un enfermement d’un autre genre. En effet, celle-ci appartient, comme on le sait, a la grande famille de la paralitterature ou se cotoient les sous-genres plus ou moins repertories en attente de recevoir un semblant de definition. Genre populaire s’appuyant sur une poetique singuliere, la SF est un lieu ouvert a l’imagination, a la creativite verbale et figurative. Elle possede elle-meme ses sous-genres, entre autres, le space opera qui fut en quelque sorte la matrice originelle de la fiction speculative et de ses emules contemporaines. L’oeuvre sternbergienne n’eut guere pour vocation de nourrir le repertoire deja riche de la science-fiction. Elle constitue neanmoins une etape non repertoriee susceptible d’apporter, nous le constaterons, une touche d’auto-reflexivite a l’histoire du genre.Keywords: Jacques Sternberg, Nouvelle, Science-Fiction, space Opera, Aventure, Fiction Speculative

In this work, the set of all functions that are Fourier transformable with regard to their structure both algebraic and topological is taken into account. Certain topological properties of the set of Fourier transformable functions with the help of a metric are described. Also determines the proofs of the statements that the set of all Fourier transformable functions is a commutative semi-group with respect to the convolution operation as well as Abelian group with respect to the operation of addition. Metric for two functions belonging to the set of all Fourier transformable functions is defined and the proof that the Fourier transformable functions space is complete with our metric is given. The separability theorem and that the Fourier transformable functions space is disConnected are also discussed.