| Summary: | 碩士 === 國立臺灣海洋大學 === 電機工程學系 === 100 === The main purpose of this thesis is to research and develop two
different kinds of battery chargers of resonant-switch converters. Starting
with the zero voltage switch (ZVS) and the converters, which employ the quasi-resonant converter (QRC) technique,we gain the best parameters of the resonance components from the characteristic curve diagrams of these two converters. Then we design battery chargers based on these two structures and use them to experiment on lead-acid batteries. According to experiments, the battery charger with the zero voltage switch quasi-resonant converter (ZVS-QRC) is turned on and turned off at the point of zero voltage, while the one with the zero current switch quasi-resonant converter (ZCS-QRC) is turned on and off at the point of zero current. The result proves that both chargers reach the resonance-switched standard. Moreover, when compared with the charger with the traditional pulse-width-modulation (PWM) converter,the charger with ZVS or ZCS quasi-resonant converters indeed lowers the temperature of the switch, resulting in the reduction of switch losses.
Subsequently, in this thesis we combine the zero voltage transition
(ZVT) soft-switched buck converter with the pulse-width modulation and
the resonance technology to maintain constant operation frequency. It is
an effective way to reduce the switch loss of the traditional hard-switching converter, filling the requirement that all circuit
components are zero voltage switched ones. In the meanwhile, two
clamping diodes can be used to lengthen the resonance period, and prevent the peak value of resonance capacitance and resonance
inductance from exceeding the voltage stresses and current ones in the
traditional pulse-width-modulation converter. Therefore, we develop a
lead-acid battery charger on the basis of the zero voltage transition
soft-switched theory. According to the result of experiments,when
compared with the traditional pulse-width-modulation converter, the zero
voltage transition soft-switching buck converter can indeed lower the
temperature of the switch, reduce the switch losses and stresses,
lengthene the lives of components, improve the whole efficiency, and
further prolong the life of lead-acid battery
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