Double-output single-phase PFC convertor and combined type power conversion system and control method thereof

Abstract

The invention discloses a double-output single-phase PFC convertor and a combined type power conversion system and control method thereof and belongs to the technical field of power electronic converters. The combined type power conversion system is composed of the double-output single-phase PFC convertor, a DC-DC circuit and a DCX circuit, the double-output single-phase PFC convertor is used for providing first direct-current voltage output and second direct-current voltage output, the first direct-current voltage output is used as input of the DCX circuit, the second direct-current voltage output is used as input of the DC-DC circuit, output of the DCX circuit and output of the DC-DC circuit are in parallel connection, and a fixed proportion is maintained between output of a first direct-current voltage of the double-output single-phase PFC convertor and output of the DCX circuit all the time and equals to the input / output voltage ratio intrinsic to the DCX circuit. By means of the double-output single-phase PFC convertor and the combined type power conversion system and control method thereof, power consumption of the PFC convertor can be decreased, the input power can be efficiently processed through the DCX circuit to the greatest extent, thereby overall efficiency is improved remarkably, and the double-output single-phase PFC convertor and the combined type power conversion system and control method thereof are particularly applicable to occasions alternating-current-direct-current electrical energy conversion with the load voltage changed substantially.

Description

technical field [0001] The invention relates to a dual-output single-phase PFC converter and its combined power conversion system and control method, belonging to the technical field of power electronic converters, especially the technical field of AC-DC electric energy conversion. Background technique [0002] Single-phase AC-DC converters are widely used in technical fields such as switching power supplies, uninterrupted power supplies, battery charging, remote communication system power supplies, and hybrid vehicles. With the continuous development of power electronics technology, electrical equipment has a harmonious power factor. The requirements of the wave are getting higher and higher. For this reason, governments and international organizations have formulated mandatory standards, such as IEC-61000-3-2, to limit the input current harmonics of the converter and improve the input power factor of the converter. The single-phase PFC converter has been widely used due to...

AI Technical Summary

Problems solved by technology

The problem with the traditional two-stage solution is that all power needs to be boosted by the front-stage PFC converter and then stepped down by the rear-stage isolated DC-DC converter. The energy is converted in two stages, resulting in increased system losses. , reduced energy efficiency

Document "P.Das, M.Pahlevaninezhad, G.Moschopoulos.AnalysisandDesignofaNewAC-DCSingle-StageFull-BridgePWMConverterWithTwoControllers[J].IEEETransactionsonIndustrialElectronics2013, 60(11): 4930-4946."A full-bridge converter is used to realize a single-stage PFC converter, only A one-stage converter is used to realize the functions of PFC and output voltage regulation at the same time, but the single-stage PFC converter either sacrifices the power factor adjustment capability, or greatly increases the voltage stress of the device, and its final effect is compared with the two-stage PFC conversion not much improvement

The above solution still uses a unified processing method for the pulsating power input by the converter, but due to the large-scale periodic fluctuation of the input AC voltage, the unified processing method cannot achieve power optimization for the entire input voltage range

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