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The following topics are dealt with : power quality parameter; power distribution reliability; power system modeling and simulation; electricity market; distributed generation interconnection; electromagnetic compatibility; energy efficiency; power grids; power quality measurement; and electrical power converter.
Different approaches to limiting the levels of electromagnetic pollution in the electrical networks are discussed. Overview of the main principles used as basis for IEC EMC standards, CIS Standard 13109-97 and IEEE Standard 519-1992 is presented. Time-varying nature of the electromagnetic processes behavior in power systems is highlighted and expressions for power quality indices based on spectral...
The recent awareness about fossil fuels and the environment has arisen more sustainable alternatives regarding means of transport. The first alternative of green transport has been hybrid vehicles. This kind of vehicles reduces significantly the CO2 emission but not totally. Nowadays, the current trend is the utilization of a unique motor for vehicle. i.e. an electrical motor. It seems that the electric...
Nowadays, a controlled electric drives (ED) are widely used in different fields of industry. Well-known that about 10 per cent of all electric power is consumed by controlled ED. In an asynchronous drive with valve cascade converter-asynchronous-valve cascade (AVC), the smooth start and speed control of the phase-wound rotor motor are realised. However, the frequency converter as a part of electric...
Power factor correction of the facilities requires a design that is able to compensate for reactive power demand as well as for harmonic currents injected by the equipment into power supply system. In the circumstances many of industrial supply systems consist of a combination of tuned filters and a capacitor bank. Investigation of interaction between capacitor banks and harmonic filters within an...
Interharmonics represent those electrical signals whose frequencies are not integer multiples of the supply fundamental frequency. They correspond to electrical components that are not synchronized with the systems fundamental frequency; due to this fact, they have a more destructive impact than harmonics on the elements of the power system. International organizations like IEC and IEEE International...
Power quality distortions such as voltage unbalance and harmonics are usually present in power supply systems (PSS) simultaneously. These distortions have effect upon the most consumers' and PPS' equipments in the similar way and lead to the power losses rise, overheating and reduction of operation life of electrical equipments. Meanwhile electromagnetic compatibility (EMC) standards set limits of...
The paper deals with analysis of electric power quality ratings in installation of an arc furnace with a battery of passive LC filters and a tracking static VAr compensation. On the basis of recorded waveforms of voltages and currents in individual circuits of an internal autonomous power network during cast process we evaluated waveforms of the electric power. Experiments were conducted for the on...
The development of a power quality (PQ) benchmarking model is presented. Practical results are discussed to motivate the need of adding value to recorded PQ data by means of benchmarking PQ performance. The importance, science and methodology of cleaning up recorded sag and swell data per site and per region is demonstrated. Benchmarking of voltage distortion, unbalance and magnitude regulation is...
It can be shown, that many flickermeters do not yield credible output readings although the manufacturers declare their compliance with the requirements of standard IEC 61000-4-15. Modifications or revisions to the standard and increasing the number of requirements, what is currently taking place, seem to be interim actions, whose results are dubious. On the other hand, it should be acknowledged that...
The number of distributed energy sources (DER), the huge increase of loads with switching supplies and the massive use of compact saving lamps brings the need to measure and evaluate voltage and current up to 9 kHz. Annex B of the latest update of the IEC 61000-4-7:2002/A1:2008 unifies the length of the basic time window for the evaluation of signal components up to 2 kHz and for the evaluation of...
Voltage transformers which are the source of the signals for electrical power network protection apparatus through transformation of high voltages to low voltages enables accurate measurement of high voltages and estimation of the power quality in the power network. Significant is then accuracy of the instrument transformer both in steady and transient states which means permissible values of the...
Proper estimation of the power quality in case of high current strength or necessary of separation between tested and measuring circuits requires determine of the level of conductive disturbances through the current transformer. The scope of the article is description of the results of the comparative laboratory research on estimation of accuracy of transfer of distorted currents through current transformers...
Short transient states during interruptions and dips of the supply voltage of the voltage transformer are the cause of low power quality and source of impulsive conductive disturbances which are transferred to secondary side of the voltage transformer. Maximal values of these impulses are able to exceed even several times rated rms values of primary and secondary voltages. This may lead to abnormal...
Peculiarities of different kinds of load in relation to produced flicker effects are presented in the paper. The analysis bases on the measurements performed in low voltage installations of an industrial object using a conventional power quality instrument. Selected types of the load: laser-cutting machines, welding devices and electrical drives were chosen in order to observe the specific properties...
Smart grid is increasingly seen as a means to facilitate climate friendly renewable energy sources (renewables) and to enable efficient use of electricity. For example, modern electrical networks can link wind- and solar power with electric cars. A consequence of smart grid is a drastic increase in use of electronics in the power system. This makes the satisfactory function of electrical and electronic...
The development of the European power systems is driven to large extent by the European energy policy formulated as directives, regulations and decisions of the European Commission and the European Parliament including compulsory standard such as for example ldquoeco-designrdquo. Despite the inertia in the implementation of the common energy policy and from time to time a lack of enthusiasm to several...
It is shown that source information ambiguity influences the accuracy of results of reactive power optimal compensation assessment, which is used as means of circuit voltage local regulation. The method of reactive power optional compensation at data flows incompleteness, which allows to fulfill normative requirements concerning power quality and derive maximum profit in the process of electrical...
The electricity grid operator should supply a voltage at a customer's installation according to the requirements of the standard EN50160 or national grid code. In contrast, no present grid codes specify clearly the responsibility of the customers regarding power quality (PQ) at their installations. The voltage flicker is one of the most irritating PQ problems on which the Dutch grid operators get...
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