EPQU Journal - Volume 13 Issue 1

Optimal number and location of measurement instruments in distributed systems for Harmonic State Estimation

By Isabelle Heriakian / Published on Sat, 2007-09-08 00:00

The recent studies about the attribution of the responsibilities for harmonic distortion in electric distribution systems show that the most promising approaches are based on measurement data acquired simultaneously in different nodes of the network. Therefore, distributed measurement systems are needed. For economic reasons, only a small part of network nodes can be equipped with measurement instruments, whereas the information about the overall status of the electric system has to be evaluated by means of suitable Harmonic State Estimation (HSE) techniques.

Read full story

Main content

Popular content

Active Current, Reactive Current, Kirchhoff's Laws and Tellegen’s Theorem

By Isabelle Heriakian / Published on Sun, 2007-09-16 00:00

The relations between the basic laws of circuit theory (Kirchhoff's laws and the conservation of generalized power) are discussed with respect to the active and reactive current components. It is shown that the active and reactive currents do not satisfy Kirchoff’s current law. It is proved that this is not in contradiction with the property that the active and reactive powers satisfy the conservation property.

Read full story

Generalized symmetrical components for periodic non-sinusoidal Three-phase signals

By Isabelle Heriakian / Published on Sat, 2007-09-15 02:30

This paper deals with the generalization of the symmetrical components technique to periodic non-sinusoidal three-phase currents and voltages. The generalization of the concept of symmetrical components is discussed together with their derivation in both time and frequency domain.

Read full story

Compensation Techniques Based on Reactive Power Conservation

By Isabelle Heriakian / Published on Sat, 2007-09-15 00:00

The paper introduces two definitions of instantaneous reactive power terms, which are conservative in every network and apply even under non-sinusoidal conditions. Both quantities coincide with usual reactive power for sinusoidal operation, however they assume a different meaning for distorted behaviour. The first one is an energy-related term, and its unbiased integral accounts for the average energy stored in the network. The second has a differential nature and is suitable for dynamic analysis and control of harmonic and reactive power sources acting in the network.

Read full story

Amplitude and Phase Modulation Effects of Waveform Distortion in Power Systems

By Isabelle Heriakian / Published on Fri, 2007-09-14 00:00

The amplitude and phase modulation effects of waveform distortion in power systems are analyzed. Recalls on Amplitude Modulation (AM) and Phase Modulation (PM) are given with particular reference to spectral components. Then, simple inverse formulas are obtained to demonstrate that summations of one or more small tones frequencies to a given tone of interest can always be interpreted in terms of AM and PM. The usefulness of AM and PM representation, in particular in the presence of interharmonic tones, is demonstrated with reference to simple case-studies and practical applications.

Read full story

Assessment of Fault Location in Power Distribution Networks

By Isabelle Heriakian / Published on Thu, 2007-09-13 00:00

Methods aimed at locating the position where a fault is occurred can be seen as part of a complex measurement system oriented at more general power quality purposes. This paper faces the comparison between two methods recently proposed in literature for fault-location in distribution networks, based on a distributed and on a single-ended measurement system, respectively. By assuming a common distribution system topology, the two methods are applied in order to compare their performances as well as the obtained results.

Read full story

1234next ›last »

Archives

Explore complete archive

Popular content