Power Factor Correction Techniques Based On Boost Converter With Universal Input Voltage Range

Capacitive rectifier, a traditional rectifier for electronics instrument, can result in a lot of input current harmonics, which brings the main to harmonics distortion. In order to limit the input current harmonics, many countries have forced to implement some limitation standards. Active power factor correction (APFC) technology can achieve high power factor and low total harmonic distortion (THD). In the past twenty years, APFC has been researched systematically and used widely. More and more electronic devices require that theirs power supply can be used in 115V and 220V main line, which means that the input voltage changes from 90V to 265V. So lots of researches have been focused on the APFC techniques with universal input voltage range.Among the typical non-isolation PFC converters, boost PFC converter has the following merits: filter inductor is in series with input terminal, which reduces the high frequency ripple of input current; output voltage is higher than peak input voltage, which can store more energy in the same size bulk capacitor; the power factor is high in the universal input voltage; simple circuit structure, low cost and high reliability. So Boost PFC converter is investigated deeply and applied widely. However in universal input application, the loss of Boost converter is high at low line. This dissertation proposes a novel control method that regulates the output voltage to vary with input voltage rms change (VVB). When low line input, the output voltage is lowered so that the duty cycle of the switch is decreased and the efficiency of the converter is improved.In low power level, power supplies are usually composed of Boost PFC stage and asymmetrical half bridge DC-DC stage. When PFC stage uses VVB control, in order to reduce the input voltage range of the next DC-DC stage, this dissertation proposes a hybrid Boost PFC converter. The voltage across the bulky capacitor of this converter can vary with the input voltage to reduce the power loss of PFC stage at low line input, and its output voltage is kept constant in the same time for the next stage. According to this converter many new topologies are induced, and its general structure is synthesized.In middle and high power level application, the phase-shift full-bridge (PS FB) is used as DC-DC stage. If the output voltage of PFC stage varies with the universal input, the input voltage range of DC-DC stage is so wide that the design and application of PS FB is very difficult. The research on the three-level DC-DC converter reveals that the hybrid full-bridge three-level (HFB TL) not only can reduce the voltage stress of the primary switches, but also can decrease the filter inductance, which fits for the wide input voltage range. The proposed approach that VVB is used as PFC stage and HFB TL as DC-DC stage can achieve high efficiency and small magnetic size. Two FB converters with different input ranges are designed and built up to compare with the proposed approach.