Quadratic voltage multiple unit DC-DC converter for photovoltaic system

Abstract

The present invention discloses a quadratic voltage multiple unit DC-DC converter for a photovoltaic system. The converter is improved in boost performance through fusion of a boost unit structure ofa voltage multiple unit compared to a traditional boost converter. Compared to a traditional boost unit of a voltage multiple unit structure, the converter has a good boost voltage performance with the increasing of a duty ratio. The quadratic voltage multiple unit DC-DC converter further fuses a quadratic boost circuit structure to further improve the voltage gain, the number of switch tubes S isnot increased, the control difficulty of the system is not increased, and the electrical stress of the switch tubes S and an output rectifier diode Do cannot be influenced. Besides, the quadratic voltage multiple unit DC-DC converter further fuses a leakage inductance clamping circuit structure to allow the energy of the leakage inductance of a coupled inductor to have a releasing loop on a basisof improving the converter boost capacity by employing the coupled inductor so as to avoid the circuit resonance problem caused by leakage inductance energy and improve the circuit efficiency.

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.

Images