Industrial Building Solutions eBook

I NDUSTR I AL BU I LDI NG SOLUT ION

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— General Reference Power quality

The public network of electric power supply is affected in a more or less relevant way by disturbances coming from the distribution networks and from the loads supplied by them that can easily lead to malfunctions and failures. In other words, the characteristics of the power supply do not always correspond to the expected ideal characteristics.

The increasing diffusion of sensitive components has progressively made previously accepted levels of power quality critical. Beyond the well-known contractual obligations that exist in the purchase, from the point of view of a user the electrical energy product is requested to have two fundamental characteristics: it should have a high availability and not cause malfunction, degradation or damage to the supplied loads. The quality of the electric energy that a generic user considers necessary for his activity is not an absolute concept, but it depends on the susceptibility of the users to the phenomena considered (technical aspect) and on the consequences of the inefficiencies (economic aspect) resulting therefore variable from case to case. In general, responsibility for satisfying this requirement depends only partially on the distribution company.

Electricity is in fact a particular product: it is never used as such by those who buy it, but it is always transformed and modified. In general terms, comparing electrical energy with other consumer products, it can be said that while the quality of most of these is completely determined by the producer and his distribution chain, in the case of electrical energy the quality of the final product is determined not only by the above mentioned figures, but also by the final consumer, or rather by the user at the very moment in which he uses it.

Moreover, achieving the best technical-economic compromise is not always easy and must be carefully evaluated.

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