Advantages and Disadvantages of Autotransformer

The autotransformer has the advantages described below:

– decrease in weight and size of equipment;

– Reduction of losses;

– Lower series impedance and better voltage regulation.        Rubber A69

And it has disadvantages:

– Loss of insulation between the primary and secondary circuits;

– It does not allow some three-phase connections, like -Y and Y-;

– The opening of the common winding will repress the secondary the same voltage imposed on the primary, which can be catastrophic when operated at high voltage levels.

– Larger fault currents, because of reduced series impedance.

Ideal transformers can be eliminated when PU units are used, however, it may be convenient to leave them simulated in the circuit as 1: 1 transformers. Thus, the multiple winding transformer admits:

– Connection of several systems operating at different voltage levels;

– When three-phase, the use of an interconnected winding for harmonic filtering, which can also be applied as power source for different loads;

– Better control of voltage regulation;

– Probability of redundancy in the supply of a critical load: two windings isolated from each other, at the same voltage level, supplying the same load;

– Power supply for auxiliary services in substations.


Notion of Electromagnetic Force

It should be emphasized that Isaac Newton was responsible for establishing a considerably causal conception of the Universe as a whole. According to this conception, all the effects observed in a general way, are caused by some forces exerted through objects found at a certain distance. In this way, from this view a search for the final cause of all forces could be initiated by means of an analogy with the gravitational mass.

The experiments of the effects of the electromagnetic force, that impacted the end of century XVIII, were widening, being the attempt to explain the mechanisms of interaction between the bodies.

Thus, scientists such as Charles Augustin de Coulomb and Henry Cavendish were able to analyze electrically charged substances and magnets by establishing the empirical laws governing their important theories, such as behavior, which indicated a possible relationship between existing forces.

It is important to understand the relationship between magnetism and electricity, which was evidenced in 1820, at which time Hans Christian Orsted, when analyzing a compass of a wire connecting the two poles of an electric cell, could conclude that the magnetic needle, instead of pointing north, was oriented perpendicular to the electric conductor.