A secondary type multi-voltage unit dc-dc converter for photovoltaic system

Abstract

The invention discloses a secondary type multi-voltage unit DC-DC converter for a photovoltaic system, which incorporates a boost unit structure of a multi-voltage unit, and compared with a traditional boost converter, the boost performance is improved; Compared with the boost unit of the traditional voltage doubler unit structure, the converter has superior boost voltage performance as the duty cycle increases. The present invention also incorporates the structure of the secondary boost circuit, the voltage gain is further improved, and at the same time, the number of switch tubes S is not increased, the difficulty of system control is not increased, and the switch tube S and the output rectifier diode D o electrical stress is not affected. In addition, the present invention also incorporates the leakage inductance clamping circuit structure, on the basis of using the coupling inductance to improve the boosting capability of the converter, the energy of the leakage inductance of the coupling inductance can be released, and the circuit resonance problem caused by the energy of the leakage inductance is avoided , and also improves the efficiency of the circuit.

Description

technical field [0001] The invention relates to a DC-DC converter, in particular to a secondary type multi-voltage unit DC-DC converter for a photovoltaic system. Background technique [0002] With the depletion of traditional fossil energy and the deteriorating environment of human beings, the development of clean renewable energy is imminent. All countries in the world are committed to the research and development of new energy applications, of which solar energy and wind energy have been obtained a wider range of applications. However, for these systems, how to operate grid-connected and meet the high voltage requirements in the grid is still the most important issue. At present, a large number of boost converters have been developed to meet these applications. Among different converters, the traditional BOOST converter can theoretically increase the voltage gain by increasing the duty cycle. However, in practical applications, due to the limitation of parasitic paramet...

AI Technical Summary

Problems solved by technology

However, in practical applications, due to the limitation of parasitic parameters, very high voltage gain cannot be achieved

If a cascaded topology is used, the problem of low efficiency caused by the increase in the number of devices will be highlighted again.

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