Analysis of Wireless Power System Efficiency in Dependency on Configuration of Resonant Tank

This chapter compares various compensation methods for resonant coupling of the wireless energy transfer system. A proposed analysis is particularly relevant to any application where contactless battery charging is used. Main parameters that are investigated include efficiency and electrical variables (current and voltage) of the circuit. In order to analyze the most suitable solution of coupling compensation, the relevant equations are graphically interpreted for each discussed circuit topology. Finally, this chapter provides the recommendations how to design the wireless power-transfer system with the highest possible efficiency for the given system parameters (switching frequency and transmitting distance)

Short-Term and Long-Term Variability of Antenna Position Due to Thermal Bending of Pillar Monument at Permanent GNSS Station

The variability of daily site coordinates at permanent GNSS station is a sum of many disturbing factors influencing the actual satellite observations, data processing, and bias modelling. In the paper are analysed possibilities of monitoring the instability of GNSS antenna pillar monument by the independent observations using the precise inclination sensor. Long-term series from three different types of pillars show specific features in amplitude and temporal evolution of monument bending. Correlations with daily temperature and/or solar radiation changes were proved

Verification of Operation Modes of Designed LLC Resonant Converter

This paper describes the design of the LLC resonant converter, which is done by means of fundamental harmonic approximation (FHA). Output power of proposed converter is 1kW with output voltage 48 V at switching frequency of 500 kHz. Performance of converter at different operational conditions was verified through simulation analysis by utilization of OrCAD PSpice software. The simulation results of multiple parametrical experiments were obtained and consequently evaluated into graphical interpretation of efficiency of proposed converter

Bidirectional Step-Up/Step-Down DC-DC Converter with Magnetically Coupled Coils

The paper is focused on bidirectional up/down DC-DC converter with magnetically coupled coils (MCC), which can be utilized as a part of power semiconductor system in traction, automotive, or industrial applications like renewable energy sources. Proposed solution of main circuit of bidirectional converter should serve for energy transfer from source to load, and vice versa, whereby parameters of electrical variables like voltage, current and power are able to be adapted based on the current requirements of application. Their values can be increased or decreased in first (energy transfer from source to load) or in third (energy transfer from load to source) quadrant of converter's operation. The boost effect of output voltage can be increased - if it is not sufficient one - by appropriate ratio of number of inductor windings

Comparison of pulsed and continuous electromagnetic field generated by WPT system on human dermal and neural cells

Abstract In recent decades, we have seen significant technical progress in the modern world, leading to the widespread use of telecommunications systems, electrical appliances, and wireless technologies. These devices generate electromagnetic radiation (EMR) and electromagnetic fields (EMF) most often in the extremely low frequency or radio-frequency range. Therefore, they were included in the group of environmental risk factors that affect the human body and health on a daily basis. In this study, we tested the effect of exposure EMF generated by a new prototype wireless charging system on four human cell lines (normal cell lines—HDFa, NHA; tumor cell lines—SH-SY5Y, T98G). We tested different operating parameters of the wireless power transfer (WPT) device (87–207 kHz, 1.01–1.05 kW, 1.3–1.7 mT) at different exposure times (pulsed 6 × 10 min; continuous 1 × 60 min). We observed the effect of EMF on cell morphology and cytoskeletal changes, cell viability and mitotic activity, cytotoxicity, genotoxicity, and oxidative stress. The results of our study did not show any negative effect of the generated EMF on either normal cells or tumor cell lines. However, in order to be able to estimate the risk, further population and epidemiological studies are needed, which would reveal the clinical consequences of EMF impact