Four-phase high-gain self-current-sharing DC-DC converter and control method thereof

Abstract

The invention provides a four-phase high-gain self-current-sharing DC-DC (Direct Current-Direct Current) converter. The four-phase high-gain self-current-sharing DC-DC converter comprises an input power supply, a four-phase boost inductor, four upper bridge arm switch tubes, four lower bridge arm switch tubes, two switch capacitors, three filter capacitors and a load which form a four-phase input network. In the four-phase input network, the input ends of four boost inductors are connected with an input power supply, the output ends of the four boost inductors are respectively connected with the drain electrodes of lower bridge arm switch tubes, S1, S2, S3 and S4 are lower bridge arm switch tubes, and S11, S22, S33 and S44 are upper bridge arm switch tubes. According to the four-phase high-gain self-current-sharing DC-DC converter provided by the invention, a coupling inductor and a transformer do not need to be used, the size of the converter is reduced, the cost is saved, and the upper bridge arm adopts a synchronous control mode, so that energy can flow bidirectionally, the operation efficiency is greatly improved, and the application scene of the converter is widened.

Description

technical field [0001] The invention relates to the field of DC-DC converters, in particular to a four-phase high-gain self-sharing DC-DC converter and a control method thereof. Background technique [0002] With the increasing consumption of fossil energy and the ecological and environmental problems it brings, human beings are eager to seek a renewable energy to replace traditional energy. New energy represented by solar energy, wind energy, etc. However, due to the low voltage generated by photovoltaic cells, it cannot be put into use directly. The usual practice is to raise its voltage to a certain value, then invert it and finally integrate it into the power grid for use. Therefore, high gain DC-DC converters play an important role in it [0003] Generally speaking, high-gain DC-DC converters can be divided into isolated and non-isolated types. Isolated converters can achieve high gain by changing the turns ratio of the isolation transformer. Large, high cost, easy to...

AI Technical Summary

Problems solved by technology

[0004] The first switched capacitor type realizes the voltage boost by charging and discharging the capacitor, but with the increase of the power level, there are higher requirements for the withstand voltage of the capacitor, and the increase of the withstand voltage value is also accompanied by the increase of the volume

[0005] The second type of coupled inductance realizes the boost through the turns ratio of the multi-winding coupled inductance, but the multi-winding coupled inductance will inevitably have magnetic flux leakage, which seriously reduces the conversion efficiency

[0006] The third cascaded type achieves high gain by connecting multi-stage converters in series, but with the increase in the number of stages, there is a problem that the voltage stress of the switch tube in the subsequent stage increases exponentially, and the deviation of the previous stage is easily amplified by the subsequent stage. end up far from the expected value

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