Non-isolated high-gain DC-DC boost converter

Abstract

The present invention belongs to the technical field of electric power and electronics, and in particularly relates to a non-isolated high-gain DC-DC boost converter. A topological unit of the converter comprises an active network, a voltage doubler rectification network, a voltage stabilizing capacitor. The active network is formed by the mutually parallel connection of two modules formed by serial connection of full control switch tubes and inductors. In the voltage doubler rectification network, two diodes are connected in series and in such a manner as a capacitor is arranged between the two diodes to form a three-terminal network. And the positive pole of the voltage stabilizing capacitor is connected with the negative poles of the diodes in the three-terminal network. The negative pole of the voltage stabilizing capacitor is connected to the negative pole of inputted voltage from the active network. The non-isolated high gain DC-DC boost converter provided in the invention can be used in a photovoltaic power generation system so as to make the voltage gain of the DC boost circuit high. With a simple control strategy and small size, small voltage stress of switch tubes in the boost topology and small current attraction can be achieved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, in particular to a non-isolated high-gain DC-DC step-up converter. Background technique [0002] With the increasing depletion of fossil energy and the pollution of the environment after burning, it has attracted more and more attention from the international community. Searching for new, renewable and non-polluting energy has become an imminent event before human beings. Due to its inexhaustible, clean and non-polluting advantages, photovoltaic power has become a key topic in people's research on future energy demand, with great potential. [0003] Since the direct output DC voltage of the photovoltaic panel in the photovoltaic power generation system is low, generally 33-43V, and for the AC220V mains, even if the full-bridge grid-connected inverter is used, the DC input bus voltage is generally 380V, how Realizing high-gain DC-DC step-up is one of the urgent problems to be solved in...

AI Technical Summary

Problems solved by technology

Some documents use the multi-level output of the Boost circuit to achieve high voltage gain, but the premise of achieving high gain is to increase the number of output levels, that is, the number of capacitors must also increase, which greatly increases the complexity of the topology. sex

Some literatures adopt the method of cascading two Boost circuits to achieve high voltage gain, but there is a control cycle difference between the two Boost circuits before and after, and the voltage stress of the switch tube in the Boost circuit in the latter stage is equal to the output voltage

Other literatures introduce switched capacitors into the Boost circuit to achieve high voltage gain. However, with the increase of the boost ratio, the number of diodes and capacitors in the circuit will increase greatly, and the current stress of the inductor is still large.

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