Utilization of the voltage rate to localization of harmonic sources in a power system
The paper proposes the new approach to determine which side, the utility or the customer is dominant harmonic source in a power system. At the beginning, review of existing approaches to localization of harmonic sources is given. Then, the theoretical background of the new approach is presented. The used criterion of localization of harmonic sources in a power system is based on examining the voltage ratio, which is defined in the paper. The results of investigation of sensibility of this ratio to the errors burdening quantities used for its calculation are analyzed. The practical conclusions are given. It is underlined that the presented approach has better properties than existing ones.
Distortion Sources Identification in Electric Power Systems
Distorted voltage and current waveforms is one of the problems associated to electric power quality. Continuous use of non-linear loads provokes the existence of voltage waveforms with a high distortion. Thus, it is necessary to know the responsible of this problem by means of the commonly named distortion sources identification. In this paper, the problem is analyzed through the harmonic power sign, with the objective of knowing the sense of harmonic power flow between source and one load in distorted systems. Nowadays, it has already been established in the Literature that an analysis of this kind does not solve the problem. Recently, new indices have been introduced to evaluate a specific consumer distortion level. In this paper, a comparative analysis of these indices is carried out, having as reference a practical case. The results obtained show that, in fact, these indices can help to valuate the harmonic distortion, although none of them solve the question definitively.
Harmonics from SVC transformer saturation with direct current offset
Circulation of direct current in transformer windings can cause significant transformer saturation and harmonic generation. This problem may be experienced by static VAr compensators with an anti-parallel thyristor arrangement. This paper presents a technique to analyze the harmonic distortions caused by transformer saturation with direct current offset. The technique is used to investigate the harmonic generation from the transformer of a static VAr compensator to be installed in the BC Hydro system. >