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Voltage dips are one of the most important power quality problems. The major disadvantage in studying this phenomenon is the difficulty to obtain the necessary data. This disadvantage is to the fact that the phenomenon is random and monitoring must be carried out for long periods of time. In these conditions the paper proposes a three-phase voltage dips software generator, by means of which voltage...
Computing systems technological development from the last period, both in terms of computing capacity and in terms of storage capacity, created the premises required to produce large databases. Meanwhile, the economic losses due to voltage dips are becoming more significant, and the result of this is an intensification of the research in this area using algorithms more complex that requires large...
The paper offers an answer to the question: a high voltage overhead line, operating in no load conditions, “generates” active power (energy)? In order to justify the answer, a case study on an untransposed 110 kV single circuit overhead line was used, for which the no load operating condition has been studied using phase amounts. For this goal, applying the modified Carson's equations and the Kron's...
Voltage dips are the most common voltage disturbance in electrical networks operation. A single phase dip is characterized by several amounts such as amplitude, phase shift, start point on wave and end point on wave. Given that electricity grids are three-phase grids and voltage dips can affect one, two or all three phases, researchers have proposed over time many methods of classifying them, which...
The increasing need to limit the harmonic pollution of electricity transmission networks, require the use of the harmonic impedance, as a primary tool of analysis. Using the general relations for calculating the harmonic impedance seen along an AC power line deducted under its modeling through a chain of two symmetric passive quadripols built with linear equivalent parameters, uniformly distributed,...
This paper presents general relations for calculation of harmonic impedance seen along an AC transmission overhead line. This is modeled by a chain of two symmetrical passive quadripoles corresponding to the segments that are on either side of the section of interest. Chain matrices of the two quadripoles are written by considering uniformly distributed line parameters and on their base, the expressions...
Due of its significant economical impact, Power-Quality (PQ) analysis is an important domain today. Severe voltage distortions affect the consumers and disturb their activity. They may be caused by short circuits (in this case the voltage drops significantly) or by varying loads (with a smaller drop). These two types are the PQ currently issues. Monitoring these phenomena (called dips or sags) require...
This paper presents a mathematical model for a complex voltage dip signal generator, that can be used to generate waveforms similar to those recorded. The voltage dip signal generator is designed to shape the voltage waveform for normal operating conditions, during the voltage dip stage and the transition between these two situations. The advantage of using a generator instead of real data measurements,...
The paper presents a fuzzy approach for harmonic voltage level based on the linguistic prescription of power quality standard. Harmonic currents are mainly generated by industrial and residential loads with non-linear characteristics. Industrial loads which are a source of significant levels of harmonic distortion include power converters, variable speed drives, induction furnaces, arc furnaces. Some...
It's very good know the interest of those that design and construct the overhead lines to attenuate the magnetic field around these, especially to earth level, because it is possible to have impact to human body. On this line one of methods there are use for reduce the magnetic field is compacting the overhead lines, such as sizing two circuits with different function on the same pole [1]. Optimizing...
Voltage sag is one of the most important problems of the power quality which affects the new sensitive equipments. For analysing the effects of voltage sag on these equipments, we need to establish a method for the voltage sags characterization. This paper presents a new method for detecting the type of voltage sags, from real-time measured data, method that will be implemented in an algorithm, for...
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