Page 11 - PEN eBook March 2023
P. 11

Power Supplies                                                                              AUTOMOTIVE



 be eliminated altogether and results in a very small increase in the power dissipated in switching,
 which is completely acceptable and insignificant.


 CONCLUSION

 Experimental results show that, with this dual-frequency methodology, the conversion efficiency
 improves by at least 6% to 7%. By performing a good analysis and design, the circuits behave as
 planned, achieving their intended goals. It is interesting to compare the voltage waveforms at the
 ends of the MOSFET and diode, at the two switching frequencies, to verify the efficiency of the
 system. It is useful, too, to analyze the currents transiting the LINV and LREC inductors.


 The oscillograms in Figure 4 show, respectively, the activation pulse of the electronic switch and its
 two signals at the ends of the two semiconductor components (the first two oscillograms above) at

 the base frequency. The other two oscillograms (bottom) show, respectively, the activation pulse of
 the electronic switch and its two signals at the ends of the two semiconductor components, at the
 double frequency. The second mode of operation uses twice the frequency and half the current on
 the load. These results, at such high frequencies, could not normally be achieved with conventional
 solutions.
            Overview of AC/DC
 Class DC/DC converters are extremely complex and critical, but they provide enormous benefits

 by allowing loads of varying nature and impedance to be driven. With special arrangements and
 substantial circuit modifications, and with an exponential increase in system complexity, a DC/DC   Converters for
 converter can also be implemented for three types of loads.
            Fast-Charging Stations





            By Saumitra Jagdale, contributing writer for Power Electronics News


            Electric vehicles constitute a major segment of the promising technologies for achieving a

            sustainable transport sector in the future. AC/DC converters are the backbone components for
                                                                                 expanding and improving
                                                                                 the functioning of EVs. This
                                                                                 article  gives  an  overview
                                                                                 of    AC/DC     converters,
                                                                                 types of charging stations,
                                                                                 problems     faced     with

                                                                                 conventional      two-level
                                                                                 (2L)   AC/DC     converters
                                                                                 and  the significance of
                                                                                 using multilevel converters
                                                                                 (MLCs).
 Figure 4: The graphs of the signals at the two operating frequencies  Figure 1: AC/DC charger illustration (Source: IES Synergy)



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