DC-DC boost converter for photovoltaic applications based on the concept of the three-state switching cell

Abstract

The present invention relates to a DC-DC boost converter for photovoltaic applications, where the DC-DC converter comprises an input terminal (14), and an output terminal (6) and a first autotransformer (37) comprising an intermediate terminal (15) and first and second end terminals (16, 17), a first diode (19), one terminal of which is coupled to said first end terminal (16), a second diode (20), one terminal of which is coupled to said second end terminal (17); where the second terminals of said diodes are connected to said output terminal (6); and where the output terminal (6) is coupled to said common terminal (8) of the converter through a first capacitor (10). In the converter according to the invention the first and second end terminals (16, 17) of the first autotransformer (37) are respectively connected to first and third terminals (55, 59) of a three-state switching cell (21), and second and fourth terminals (56, 60) of the three-state switching cell (21) are connected to the common terminal (8) of the converter. Preferably, the converter of the invention is provided with a snubber circuit (36, 18) between the input terminal and the output terminal of the converter in order to minimize the recovery current of boost diodes added to the three-state switching cell.

Description

technical field [0001] The present invention relates generally to power conversion, and more particularly to PV power conditioning systems with maximum power point tracking (MPPT) and ultra-efficient DC-DCPWM converters for harvesting solar energy. Background technique [0002] AC-DC and DC-DC converters are increasingly developing towards high efficiency, high power density and low cost. Due to the inherent characteristics of PWMAC / DC and DC-DC converters and the fact that it is easy to add soft switching units in the main topology circuit, it is easier to achieve high efficiency. In addition, the magnitude of the reactive component can be reduced by increasing the switching frequency. [0003] However, in high-voltage and high-power application scenarios, soft-switching PWM converters still have certain defects. For example, the high voltage applied to both ends of the switch and the high peak current through the switch will cause a large amount of power loss and a large ...

AI Technical Summary

Problems solved by technology

[0012] In today's existing solutions, either choose to optimize efficiency or choose to optimize high density, but both cannot be optimized at the same time, and no matter which one is chosen, the cost of the corresponding solution is not low

[0013] Traditionally, the increased DC power requirement can be addressed using paralleled converters, but this is not an optimal solution with high efficiency, high power density, and low cost due to the above-mentioned issues

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