Search results for " reactive power"
showing 10 items of 14 documents
Comparison of Nonactive Powers for the Detection of Dominant Harmonic Sources in Power Systems
2008
This paper deals with an innovative technique for the detection of disturbing loads in distorted power systems. The technique is a single-point strategy based on a comparison among different ldquononactiverdquo power quantities already proposed in the literature, which are measured at the same metering section. In this paper, the effectiveness of the strategy is discussed, which also considered the errors of the measurement transducers; the analysis is supported by simulation tests, which were carried out on both a simple single-phase system and an IEEE standard three-phase test power system. The latter was used by other authors as a benchmark system for the analysis of multipoint measureme…
Ancillary Services in the Energy Blockchain for Microgrids
2019
The energy blockchain is a distributed Internet protocol for energy transactions between nodes of a power system. Recent applications of the energy blockchain in microgrids only consider the energy transactions between peers without considering the technical issues that can arise, especially when the system is islanded. One contribution of the paper is, thus, to depict a comprehensive framework of the technical and economic management of microgrids in the blockchain era, considering, for the first time, the provision of ancillary services and, in particular, of the voltage regulation service. When more PV nodes are operating in the grid, large reactive power flows may appear in the branches…
A single-point approach based on IEEE 1459-2000 for the identification of prevailing harmonic sources detection in distorted three phase power systems
2009
This paper deals with a novel single-point strategy for the detection of prevailing harmonic sources downstream or upstream the metering section in three-phase power systems. It is an enhancement of a previous strategy, already developed by the authors and it is based on the comparison of three non-active power quantities which are based on the IEEE Std. 1459-2000 approach. The method does not require any spectral analysis of voltages and currents because it is based only on the separation of the fundamental components from the harmonic content of voltage and current. In the paper, the effectiveness of the strategy is investigated by means of simulation tests which were carried out on a IEE…
Detection of disturbing loads in distorted and/or unbalanced power systems: a technique based on a comparison among nonactive powers
2007
This paper presents an innovative technique for the detection of disturbing loads in distorted power systems. It is a single-point strategy, based on a comparison among different "nonactive" power quantities already proposed in literature, that are measured at the same metering section. In the paper, the results obtained with the application of the proposed technique are compared with those of other techniques for the monitoring of the harmonic pollution, both single-point and multi-point. Moreover, the effectiveness of the strategy is discussed, considering also the errors of the measurement transducers.
Riferibilità dei contatori statici di energia reattiva in presenza di armoniche. Evoluzione normativa e prove sperimentali
2013
The Measurement of Reactive Energy in Polluted Distribution Power Systems: An Analysis of the Performance of Commercial Static Meters
2008
This paper presents a comparative analysis of the performances of both a traditional induction meter and various types of commercial static meters for reactive energy in the presence of harmonic distortion. This is a topical issue, since there are several types of static meters on the market, based on different principles of construction. In accordance with current standards, these meters are designed to operate in sinusoidal conditions and their performance is not tested in the presence of harmonic distortion. However, with the increase of pollution levels in power systems, the meters may be used even in the presence of distorted voltages and/or currents; in such cases, their accuracy may …
IEEE Std 1459–2010. IEEE Standard Definitions for the Measurement of Electric Power Quantities under Sinusoidal, Nonsinusoidal, Balanced or Unbalance…
2010
Definitions used for measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, or unbalanced conditions are provided in this standard. Mathematical expressions that were used in the past, as well as new expressions, are listed, as well as explanations of the features of the new definitions.
Constrained Robust MultiObjective Optimization for Reactive Design in Distribution Systems
2006
This paper presents a new formulation including robustness of solution of constrained multiobjective design or reactive power compensation. The algorithm used for optimization is the NSGA-II (Non dominated Sorting Genetic Algorithm II) with a special crowded comparison operator for constraints handling. The need for including the issue of robustness of solutions derives from the simple observation that loads are uncertain in distribution systems and their estimation is often affected by errors. In design problems it is desirable to consider the loads with a certain range of variation. In this paper the NSGA-II algorithm is applied to efficiently solve the issue and the solutions attained co…
Disturbing loads identification in power systems: a single-point time-domain method based on IEEE 1459-2000
2009
This paper presents a single-point method for the identification of prevailing disturbing loads in power systems for both single-phase and three-phase applications downstream or upstream from the metering section. It is based on the simultaneous measurement of three nonactive power quantities, which are based on the IEEE Std. 1459-2000 approach. The proposed method is only based on the separation of the fundamental components from the harmonic content of voltage and current; thus, it does not require any spectral analysis of the voltages and current. In this paper, the formulation of the proposed method and its time-domain implementation are described; moreover, some simulation results are …
Traceability of static reactive energy meters in the presence of harmonics: theoretical considerations and a DAQ-based reference meter
2013
This paper deals with some problems related to the measurements traceability with static meters for reactive energy. These problems arise when the meters operate in the presence of harmonics, which can negatively affect their performances, depending on implemented metric. The paper analyzes the problem in the light of both in-force and draft standards, from the viewpoint of the performances of both commercial meters and reference standard instruments. The analysis is supported by some experimental tests, which are carried out by means of a reference meter, based on data acquisition boards, which can be used in both sinusoidal and distorted conditions.