Ferrite and iron powder magnetic materials were developed to support a wide range of components, including inductors, EMI suppressors, conventional transformers and transmission line transformers (TLTs). This article deals with transmission line transformers, presenting the observations and conclusions of the author, reached after extensive experimental research into the behavior and performanc...

Partial discharges (PD) are recognized as the main cause of the inner insulation deterioration process in power transformers. Therefore, the optimum inner insulation design is one of the challenges a transformer designer is faced with. Transformer strength, especially during transient conditions, is a criterion for transformer insulation designers. This challenge has made designers initiate and...

Task assignment problem (TAP) involves assigning a number of tasks to a number of processors in distributed computing systems and its objective is to minimize the sum of the total execution and communication costs, subject to all of the resource constraints. TAP is a combinatorial optimization problem and NP-complete. This paper proposes a hybrid meta-heuristic algorithm for solving TAP in a ...

The most important parameter in transformers life expectancy is the hot-spot temperature level which accelerates the rate of aging of the insulation. The aim of this paper is to present thermal models for transformers loaded at prefabricated MV/LV transformer substations and outdoor situations. The hot-spot temperature of transformers is studied using their top-oil temperature rise models. The ...

We argue that the category of transformers of monotonic predicates on posets is superior to the category of transformers on pow-ersets, as the basis for a calculus of higher order imperative programming. We show by an example polytypic program derivation that such transformers (and the underlying categories of order-compatible relations and monotonic functions) model a calculus quite similar to...

INTRODUCTION THE electricity grid is an essential part of our social infrastructure, and with moves to protect the global environment gaining momentum internationally there is a strong need for environmental measures based on efficiency gains and other initiatives that make effective use of the materials and equipment that comprise the grid. The efficiency characteristics of amorphous transform...

We present a compositional semantics and analysis framework for hierarchical block diagrams (HBDs) in terms of atomic and composite predicate transformers. Our framework consists of two components: (1) a compiler that translates Simulink HBDs into an algebra of transformers composed in series, in parallel, and in feedback; (2) an implementation of the theory of transformers and static analysis ...

A compositional weakest precondition semantics is given for a parallel language with recursion using a new metric resumption domain. By extending the classical duality of predicate vs. state transformers, the weakest precondition semantics for the parallel language is shown to be isomorphic to the standard metric state transformer semantics. Moreover , a notion of reenement for predicate transf...

Bond graph models of an electrical transformer including the nonlinear saturation are presented. These models determine the relation between self and mutual inductances, and the leakage and magnetizing inductances of power transformers with two and three windings using the properties of a bond graph. The modelling and analysis using this methodology to three phase power transformers or transfor...