Реферат на тему: Анализ проблем оценки качества электроэнергии
In recent years power quality issues have captured the attention of many researchers, energy suppliers and customers. The problem of controlling power quality is becoming more relevant because of the widespread use of non-linear and time-varying single-phase or three-phase loads that increasingly affect the operation of distribution networks in residential, commercial and industrial areas. Power quality deterioration is due to transient disturbances (voltage sags, voltage swells, impulses, etc.) and steady-state disturbances (harmonic distortion, unbalance, flicker). The main causes of such disturbances as well as the detrimental effects they have on the electrical systems are described. Among these issues, harmonics are investigated more accurately in this article. Some definitions relevant to non-sinusoidal systems are provided in order to deeply understand the solutions proposed in the remainder. A topic several researchers are interested in is that non-linear loads should not be considered the only cause of the detrimental effects related to power systems. The responsibility for the power quality deterioration should be shared between the supplier and the customer. This kind of information could be provided by indices in a straightforward and simple way. The traditional indices used by the international standards cannot satisfy these specifications. To this purpose, a new index to evaluate the above-mentioned harmonic distortion phenomena in the supply electrical networks is more deeply discussed.
1. Analysis of Power Quality problems
Electricity is an essential aspect of today’s society. That is why such a valuable product rules the majority of the political and strategic choices. Moreover, the industrial and economical development of a country has to be sustained by an adequate amount of electricity produced. To some extent, electricity is the "first" product to be produced. Notwithstanding, over the last few years, the analysis of operation of the electrical systems has proved that the electrical energy should not be considered in terms of "quantity" alone. The "quality" of the supply is a serious issue to be addressed as well (Dugan et al., 1996; Arrillaga et al., 2000). In fact, like other industrial products, electrical energy is required to meet some quality requirements: the reliability of the supply must be known in terms of the continuity of service and the paramet......