High-gain isolated-type active clamping soft-switched DC-DC convertor

Abstract

The invention discloses a high-gain isolated-type active clamping soft-switched DC-DC convertor, and belongs to the technical field of convertors. The convertor comprises a current multiplication loop, a transformer and a switched capacitance loop; the current multiplication loop comprises a voltage source Vin, two input inductors L1 and L2, a clamping capacitor Cc, two main power switch tubes S2 and S4, two auxiliary power switch tubes S1 and S3, external capacitors CS1, CS2, CS3 and CS4 of the four power switch tubes S1-S4, and a transformer primary coil shunt inductor L; the switched capacitance loop comprises four rectifier diodes which include D1, D2, D3 and D4, one resonance inductor Llk, two resonant capacitors C11 and C12, two output capacitors C21 and C22, and a load resistor R. The high-gain isolated-type active clamping soft-switched DC-DC convertor has the advantages of having high gain, being small in ripple of input current, small in ripple of output voltage, low in cost, and high in efficiency, and can be applied to occasions of conversion from direct current to direct current in low-voltage and large-current systems like a photovoltaic power generation system and a fuel-cell power generation system.

Description

technical field [0001] The invention relates to a converter in the field of electrical technology, in particular to a high-gain isolated active-clamp soft-switching DC-DC converter, which can be applied to low-voltage and high-current systems such as photovoltaic power generation systems and fuel cell power generation systems Medium DC to DC conversion occasions. Background technique [0002] In low-voltage, high-current power supply systems such as photovoltaic power generation systems and fuel cell power generation systems, DC-DC converters are key components for transferring voltage and current, realizing energy conversion and power control. Considering the low-voltage and high-current characteristics of photovoltaic power generation systems and the realization of grid-connected functions, the design of converters has the following requirements: high gain, small input current ripple, small output voltage ripple, low cost, and high efficiency . [0003] Conventional boos...

AI Technical Summary

Problems solved by technology

The basic full-bridge circuit has two pairs of switch bridge arms, and the two power switches of each bridge arm conduct complementary conduction at 180°. The conduction phase angle of the two bridge arms differs by one phase (that is, the phase shift angle). The disadvantage is that it is difficult to realize the soft switching of the lagging bridge arm, the circuit gain is small, and the input current fluctuates greatly. Generally, DC-DC converters will be supplemented and improved on the basis of full-bridge converters.

Chinese invention patent ZL201310302150.3 involves a high-gain isolated DC-DC converter. The converter has the advantages of large voltage gain and small input current and output voltage ripple. The disadvantage is that it does not realize the soft switching of the main power switch. Large loss and low efficiency

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