Wyniki wyszukiwania - BazTech

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Theoretical analysis of the efficiency of a V2G wireless charger for electric vehicles

Triviño Alicia, Gonzalez-Gonzalez Jose M., Aguado Jose A.

Transactions on Environment and Electrical Engineering

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2019

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Vol. 3, No. 1

9--14

EN

V2G (Vehicle-to-grid) technology will report important benefits for the operation and safety of the grid. In order to facilitate the expansion of the V2G technology in a future, it is recommended to offer the drivers with easy to use methods to charge and discharge their EV batteries. In this sense, wireless chargers are expected to play a relevant role in the future electrical networks as it reduces the users intervention. The development of this kind of system is still open to improve them in terms of their operation, their compliance and their control. An important issue for the evaluation of these systems is the efficiency, which measures the power losses occurring in the system. This paper addresses a deep study about the losses in a bidirectional wireless charger. Then, it provides with a mathematical model to characterize them. This model is validated by means of experimental results conducted in a 3.7-kW prototype.

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Monitoring of phase jitter in fibre optic time and frequency transfer systems

Salwik K., Śliwczyński Ł., Krehlik P.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 3

487--497

EN

The phase jitter enables to assess quality of signals transmitted in a bi-directional, long-distance fibre optic link dedicated for dissemination of the time and frequency signals. In the paper, we are considering measurements of jitter using a phase detector the detected frequency signal and the reference signal are supplied to. To cover the wideband jitter spectrum the detected signal frequency is divided and - because of the aliasing process - higher spectral components are shifted down. We are also examining the influence of a residual jitter that occurs in the reference signal generated by filtering the jitter occurring in the same signal, whose phase fluctuations we intend to measure. Then, we are discussing the evaluation results, which were obtained by using the target fibre optic time and frequency transfer system.

3

A bidirectional DC-DC converter for renewable energy systems

Jałbrzykowski S., Citko T.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2009

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Vol. 57, nr 4

363-368

EN

To improve the energy quality, most of the renewable energy systems include an energy storage element charged by the bidirectional DC-DC converter. This paper proposes the bidirectional DC-DC converter which employs the two bridge configuration resonant class-E converters on the both sides of the isolating transformer. The low side converter is controlled as step up and the high side converter is controlled as step down. The proposed system is characterized by good dynamic properties and high efficiency because the converter transistors are switched in ZVS conditions. A theoretical analysis to provide relations for system design, and the laboratory model investigations to validate the system characteristic are given in the paper.